[Request] Support iOS

[markvideon]

Would be great to see this package support iOS.

At a surface level, the existing plugin implementation for macOS looked very portable to iOS. The Game Controller library from Apple supports both platforms.

I made an attempt myself, and porting the code was relatively straightforward - updating the conditional compilation checks with the iOS platform name and version numbers, and a small tweak to the reference to the binary messenger.

[markvideon]

Worth keeping an eye on this - proposal to share code between iOS and macOS plugins.

https://docs.google.com/document/d/1JdgBrMXV0a6fnVoooILNTQB8dNCvLloT4D4TBkECQ6c/edit?resourcekey=0-iPL3CzwOjUquabkMiucaHA

[markvideon]

Done!