feat: New Core/ library (#1975)

Moves everything Camera related into `core/` / `Core/` so that it is better encapsulated from React Native.

Benefits:

1. Code is much better organized. Should be easier for collaborators now, and cleaner codebase for me.
2. Locking is fully atomically as you can now only configure the session through a lock/Mutex which is batch-overridable
    * On iOS, this makes Camera startup time **MUCH** faster, I measured speedups from **1.5 seconds** to only **240 milliseconds** since we only lock/commit once! 🚀 
    * On Android, this fixes a few out-of-sync/concurrency issues like "Capture Request contains unconfigured Input/Output Surface!" since it is now a single lock-operation! 💪 
3. It is easier to integrate VisionCamera outside of React Native (e.g. Native iOS Apps, NativeScript, Flutter, etc)

With this PR, VisionCamera V3 is up to **7x** faster than V2

package/ios/Extensions/AVCaptureVideoDataOutput+pixelFormat.swift

@@ -0,0 +1,26 @@
+//
+//  AVCaptureVideoDataOutput+pixelFormat.swift
+//  VisionCamera
+//
+//  Created by Marc Rousavy on 12.10.23.
+//  Copyright © 2023 mrousavy. All rights reserved.
+//
+
+import AVFoundation
+import Foundation
+
+extension AVCaptureVideoDataOutput {
+  /**
+   Gets or sets the PixelFormat this output streams in.
+   By default, the first item in `availableVideoPixelFormatTypes` is chosen.
+   */
+  var pixelFormat: OSType {
+    get {
+      let current = videoSettings[String(kCVPixelBufferPixelFormatTypeKey)] as? OSType
+      return current ?? availableVideoPixelFormatTypes.first!
+    }
+    set {
+      videoSettings[String(kCVPixelBufferPixelFormatTypeKey)] = newValue
+    }
+  }
+}