Add macOS support

[tashcan]

This depends on #24

• Port all remaining things in mods to mac, all code there now compiles and runs on both mac and windows
• Add a new macos-dylib, this is the actual patch on mac and is analogous to win-proxy-dll for windows
• Add a macos-loader, this is required as we have to launch the game using some environment variables, so we use that a jumper
• Add a macOS App that acts as a simple launcher, this packages all the required binaries and libs to actually launch the game with the patch installed
• Setup CI and built scripts to build and bundle everything into a .dmg file that we can distribute to players (this is unsigned, so we'll have to provide instructions on how to run that)
• Various small code cleanups here and there

Fixes: #16