feat: add -compile flag to compile definitions

[Pistonight]

When releasing the mod people probably want their definitions all compiled and packaged with the release
However if you don't already have these ".compiled" files then the game only lazy-compile them when EnsureDefinitionsLoaded is manually called somewhere.
This is not convenient when say you add your own definitions..

With this change, after building the exe, people can run it with -compile command to ensure all definitions are compiled, then they can pack that into the pak with the release. When running with -compile, the game will just compile the things and exit, so it can be run in automation (it still tries to show the window, since that's hardcoded in SexyAppBase and I didn't want to touch that in case I break something)

With this also supports loading compiled definitions from pak

Also made some small modernization changes