Meshing, ARKit Mesh Classification, and Anchors support

Huge thanks for all supporters, the plugin is evolving because of you!

Meshing support (ARMeshManager).

Meshing was a highly requested feature for a long time and now it's here! Currently, the iPad 2020 with LiDAR is the only mobile device that supports meshing. But, theoretically, the plugin should support meshing on Magic Leap and Holo Lens too. I have no way to prove it without the actual devices, so if you have one, your help would be very appreciated (Holo Lens, Magic Leap).

Also, the ARKit Mesh Classification is supported. Here is a video that shows the classification in action:

Anchors support (ARAnchorManager).

Previously, it was impossible to support ARAnchorManager in Editor, because its API is synchronous. This means that a call to ARAnchorManager.AddAnchor() should return instantly: and I can't make an instant network request to the companion app using built-in Unity connection.

Happy news! The transition from Unity built-in connection to Telepathy TCP gave me the ability to fully control the connection between Editor and AR device. Now I can send a message from Editor to the companion app, then block the Editor's main thread while waiting for the response in background thread. This results in small hiccups (10-20ms) in the Editor, but allows me to add the full support of ARAnchorManager.

Changes in ARKit Blendshapes.

I refined the way ARKit Blenshapes was received in Editor. Previously, you were required to write a lot of #defines and get Blendhshapes in Editor from BlendShapeCoefficientsContainer.cs. Now, the only change you need to make to your scripts that deal with Blenshapes is this one:

Code (CSharp):

1. #if UNITY_EDITOR
2. using ARKitFaceSubsystem = ARFoundationRemote.Runtime.FaceSubsystem;
3. #endif

Bug fixes:
- Disable camera video in Windows Unity Editor 2019.2 to prevent crash.
- Fixed: UI Event System is not working after loading new AR scene at runtime.
- Fixed: BoundedPlane.center should be in local space coordinates instead of the world.
- Fixed: sometimes the IP will not be shown in AR Companion app on Android.