Checklist for 2.206/breaking changes

[matcool]

• [x] Remove ghc::filesystem (#713)
• [x] Remove sync web request utils
• [x] Remove old web utils, switch to web2
• [x] Merge new index branch? (#712)
• [x] queueInMainThread should take in a move only function
• [x] Remove gd shorthand (#471)
• [x] Remove old fields syntax (#715)
• [x] merge win-64 branch, if the game is even 64 bit
• [x] Remove todoreturn (#714)
• [x] M1 macos support
• [x] Mod updating for the new index
• [x] Remove unused string/wstring utilities
• [x] Update CLI to use new index for mod dependencies
• [x] Add /v1/developers to index
• [x] ~~Tasks mappers should be allowed to return void~~ Task::listen
• [x] things using is_json silently fail if not implemented
• [x] rename windows platform to Win64, remember to update codegen
• [x] ~~fix? android64 exceptions by using c++_shared stl~~ postponed
• [x] use tasks in older apis (file picker)
• [x] implement new file picker api on other platforms

not abi breaks:

• [ ] fix android gd version check for mods
• [ ] Finish CLI index utils
• [x] Tackling windows compile times
• [x] Fix xmm0 on delayload