fix(UI): gunmod wield info no longer causes game to crash

[chaosvolt]

Checklist

Required

• I wrote the PR title in conventional commit format.
• I ran the code formatter.
• I linked any relevant issues using github keyword syntax so it can be closed automatically.
• I have committed my changes to new branch that isn't main so it won't cause conflict when updating main branch later.

Optional

Purpose of change

This fixes a mistake I made in #4183 where UI changes did not play well with uninstalled gunmods.

Fixes #5132

Describe the solution

In character_functions.cpp, updated fmt_wielded_weapon so that the gun UI stuff only calls for gun_current_mode if the affected item is a valid gun and not an isolated gunmod. Gunmods also no longer try to display fire mode since it's not relevant to gunmods that can't be fired when uninstalled.

Describe alternatives you've considered

Just slapping && !weapon.is_gunmod() to the opening if statement would be a braindead easy hack to fix this but would make it so wielded gunmods no longer show you their (technically irrelevant due to not being able to fire) loaded ammo in wield info.

Testing

1. Compiled and load-tested.
2. Wielded an M4, M203, and an M4 with M203 installed on it.
3. No crashes when wielding a gunmod anymore, info displayed when wielding the M203 is also fixed.
4. Checked affected file for astyle.

M4:

Loose M203:

M4 with M203 installed:

M4 with M203, M203 selected:

Additional context

[chaosvolt]

@scarf005 so that change proposal borked it:

1>C:\Users\Vincent\Documents\GitHub\Cataclysm-BN\src\character_functions.cpp(458,72): error C2678: binary '+=': no operator found which takes a left-hand operand of type 'const std::string' (or there is no acceptable conversion)
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\include\xstring(3084,42): message : could be 'std::basic_string<char,std::char_traits<char>,std::allocator<char>> &std::basic_string<char,std::char_traits<char>,std::allocator<char>>::operator +=(_Elem)'
1>        with
1>        [
1>            _Elem=char
1>        ] (compiling source file ..\src\character_functions.cpp)
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\include\xstring(3080,42): message : or       'std::basic_string<char,std::char_traits<char>,std::allocator<char>> &std::basic_string<char,std::char_traits<char>,std::allocator<char>>::operator +=(const _Elem *const )'
1>        with
1>        [
1>            _Elem=char
1>        ] (compiling source file ..\src\character_functions.cpp)
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\include\xstring(3069,42): message : or       'std::basic_string<char,std::char_traits<char>,std::allocator<char>> &std::basic_string<char,std::char_traits<char>,std::allocator<char>>::operator +=(const std::basic_string<char,std::char_traits<char>,std::allocator<char>> &)' (compiling source file ..\src\character_functions.cpp)
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\include\xstring(2935,42): message : or       'std::basic_string<char,std::char_traits<char>,std::allocator<char>> &std::basic_string<char,std::char_traits<char>,std::allocator<char>>::operator +=(std::initializer_list<_Elem>)'
1>        with
1>        [
1>            _Elem=char
1>        ] (compiling source file ..\src\character_functions.cpp)
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\include\xstring(3075,42): message : or       'std::basic_string<char,std::char_traits<char>,std::allocator<char>> &std::basic_string<char,std::char_traits<char>,std::allocator<char>>::operator +=<std::basic_string<char,std::char_traits<char>,std::allocator<char>>,0>(const _StringViewIsh &)'
1>        with
1>        [
1>            _StringViewIsh=std::basic_string<char,std::char_traits<char>,std::allocator<char>>
1>        ] (compiling source file ..\src\character_functions.cpp)
1>C:\Users\Vincent\Documents\GitHub\Cataclysm-BN\src\character_functions.cpp(458,72): message : while trying to match the argument list '(const std::string, std::basic_string<char,std::char_traits<char>,std::allocator<char>>)'
1>C:\Users\Vincent\Documents\GitHub\Cataclysm-BN\src\character_functions.cpp(460,74): error C2678: binary '+=': no operator found which takes a left-hand operand of type 'const std::string' (or there is no acceptable conversion)
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\include\xstring(3084,42): message : could be 'std::basic_string<char,std::char_traits<char>,std::allocator<char>> &std::basic_string<char,std::char_traits<char>,std::allocator<char>>::operator +=(_Elem)'
1>        with
1>        [
1>            _Elem=char
1>        ] (compiling source file ..\src\character_functions.cpp)
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\include\xstring(3080,42): message : or       'std::basic_string<char,std::char_traits<char>,std::allocator<char>> &std::basic_string<char,std::char_traits<char>,std::allocator<char>>::operator +=(const _Elem *const )'
1>        with
1>        [
1>            _Elem=char
1>        ] (compiling source file ..\src\character_functions.cpp)
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\include\xstring(3069,42): message : or       'std::basic_string<char,std::char_traits<char>,std::allocator<char>> &std::basic_string<char,std::char_traits<char>,std::allocator<char>>::operator +=(const std::basic_string<char,std::char_traits<char>,std::allocator<char>> &)' (compiling source file ..\src\character_functions.cpp)
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\include\xstring(2935,42): message : or       'std::basic_string<char,std::char_traits<char>,std::allocator<char>> &std::basic_string<char,std::char_traits<char>,std::allocator<char>>::operator +=(std::initializer_list<_Elem>)'
1>        with
1>        [
1>            _Elem=char
1>        ] (compiling source file ..\src\character_functions.cpp)
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\include\xstring(3075,42): message : or       'std::basic_string<char,std::char_traits<char>,std::allocator<char>> &std::basic_string<char,std::char_traits<char>,std::allocator<char>>::operator +=<std::basic_string<char,std::char_traits<char>,std::allocator<char>>,0>(const _StringViewIsh &)'
1>        with
1>        [
1>            _StringViewIsh=std::basic_string<char,std::char_traits<char>,std::allocator<char>>
1>        ] (compiling source file ..\src\character_functions.cpp)
1>C:\Users\Vincent\Documents\GitHub\Cataclysm-BN\src\character_functions.cpp(460,74): message : while trying to match the argument list '(const std::string, std::basic_string<char,std::char_traits<char>,std::allocator<char>>)'
1>C:\Users\Vincent\Documents\GitHub\Cataclysm-BN\src\character_functions.cpp(462,31): error C2678: binary '+=': no operator found which takes a left-hand operand of type 'const std::string' (or there is no acceptable conversion)
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\include\xstring(3084,42): message : could be 'std::basic_string<char,std::char_traits<char>,std::allocator<char>> &std::basic_string<char,std::char_traits<char>,std::allocator<char>>::operator +=(_Elem)'
1>        with
1>        [
1>            _Elem=char
1>        ] (compiling source file ..\src\character_functions.cpp)
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\include\xstring(3080,42): message : or       'std::basic_string<char,std::char_traits<char>,std::allocator<char>> &std::basic_string<char,std::char_traits<char>,std::allocator<char>>::operator +=(const _Elem *const )'
1>        with
1>        [
1>            _Elem=char
1>        ] (compiling source file ..\src\character_functions.cpp)
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\include\xstring(3069,42): message : or       'std::basic_string<char,std::char_traits<char>,std::allocator<char>> &std::basic_string<char,std::char_traits<char>,std::allocator<char>>::operator +=(const std::basic_string<char,std::char_traits<char>,std::allocator<char>> &)' (compiling source file ..\src\character_functions.cpp)
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\include\xstring(2935,42): message : or       'std::basic_string<char,std::char_traits<char>,std::allocator<char>> &std::basic_string<char,std::char_traits<char>,std::allocator<char>>::operator +=(std::initializer_list<_Elem>)'
1>        with
1>        [
1>            _Elem=char
1>        ] (compiling source file ..\src\character_functions.cpp)
1>C:\Users\Vincent\Documents\GitHub\Cataclysm-BN\src\character_functions.cpp(462,31): message : while trying to match the argument list '(const std::string, const char [2])'
1>Done building project "Cataclysm-lib-vcpkg-static.vcxproj" -- FAILED.

[chaosvolt]

Aight, it compiles and works same as the initial method did.