Also fix font editor builds on windows and add more font editor builds to the ghactions workflow.
Funny, we don't really need resource.h anymore. The resource compiler does, but we don't.
Also write PNGs with libpng, and BMPs with SDL, and have the renderer only generate a large PNG thumbnail, and disable HTTP/2 multiplexing for now so we don't get banned when loading avatars.
simon pls reply to the stupid emails already.
Also Factor out app constants that mods might change into Meson options and clean up format::URLEncode in the process, convert app and document icon data in arrays to actual images, actualize AppStream data for possible future packaging, add alternative command line format for opening filesystem saves and ptsave URLs, fix a memory leak in Platform::GetCwd, and add format::URLDecode.
Also fix the first mouse click not being detected on windows with sdl 2.0.20. Apparenlty, we need SDL_HINT_MOUSE_FOCUS_CLICKTHROUGH set to 1 for it to be detected.
These got lost in the migration to Meson; they used to be called
with atexit, but this caused more problems than it should have.
Anyway, it's fine to call these only when we're exiting normally,
since otherwise we have bigger problems than not quitting SDL.
