VisionOS support

[jfperusse]

Documentation

https://developer.apple.com/documentation/compositorservices/layer_renderer

https://developer.apple.com/documentation/compositorservices/drawing_fully_immersive_content_using_metal

References

bkaradzic/bgfx#3292

Checklist: Checklist

• Initial compilation

• Merge into main

• Update bgfx

• Update bx

• Replace SVProgressHUD

• Implement OpenAL stuff (playSoundAsset, etc.)

• Bug: Cannot use Edit/Actions/Play with eye interaction (move to ornaments)

• Fix crashes (play, restart, etc.)

• Need some way to indicate that legacy projects are not supported

• Support windowed modern projects

• Support immersive projects

• Bring back custom changes in bgfx

• Sidebar is all white