Order now matches the UI more closely

Now the argument parsing is separated into functions for each
GameScope 'category' on the UI, it was getting to be a bit of
a pain to manage all of these arguments.

Adds ITM (Inverse Tone Mapping) options to the HDR section.
These were added semi-recently to GameScope.
Also fixes a bug where one of the already-existing arguments was not properly escaped.

Adds '--expose-wayland' option as checkbox.
Adds the three new GameScope HDR options to UI.
Minor code refactor.

We now have a general function to do the grepping for GameScope args.
This is still WIP but has massively reduced the repeated logic for some
checkboxes.

This will be experimented with and expanded for other checkboxes, but
this should significantly simplify the GameScope argument logic.

Also has some other refactoring.

Also fixes a bug where max scale factor was using the wrong flag check.

Also improve getGameScopeArg to use Bash parameter expansion instead of sed.

no idea what this was or when it appeared...

Created setGameScopeVars to help trim down GameScopeGui.

This wasn't working before, but seems to be working now? I have no idea.

…ctly

If there was a single-dash flag after a double-dash flag,
for example '--cursor /path/to/cursor.png -U --sharpness-value 5',
then the cursor path would contain the following single-dash flag(s)
up until the next double dash flag, meaning the path would be read as
invalid.

This fixes the issue. It was not introduced in this PR but has been
fixed!

Previously we used 'mapfile', which we can't use now because
some arguments may have spaces in their path.

We use new logic now using readarray and some sed magic to
break up the gamescope arguments and build each argument and its value
separately.

This reverts commit eb897a4.

We use some fancy sed and grep commands to do this.
ChatGPT actually generated the sed command to surround unquoted paths with quotes.