Quickfix to avoid parse errors in verbatim environments

[PHPirates]

Part of #101

Syntax highlighting of \end in verbatim environments is wrong: haven't found yet where exactly this highlighting is done

Summary of additions and changes

• Add a heap of lexer states to go into and out of a verbatim lexer state. Also uses a token remapper to clean up leftover \end{ and whitespace which should be raw text.
• Removed inspection which warns for verbatim, one of the quickfixes is a new intention

How to test this pull request

            \begin{verbatim}
                $
                \end{no verbatim} }
                \begin{alsonoverbatim}
            \end{verbatim}
            
            $ math$

[slideclimb]

• \end{} inside verbatim (with empty argument) causes parse error
• Enter on verbatim autocompletion creates two new lines