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/Core/CameraSessionDelegate.swift

@@ -0,0 +1,32 @@
+//
+//  CameraSessionDelegate.swift
+//  VisionCamera
+//
+//  Created by Marc Rousavy on 11.10.23.
+//  Copyright © 2023 mrousavy. All rights reserved.
+//
+
+import AVFoundation
+import Foundation
+
+/**
+ A listener for [CameraSession] events
+ */
+protocol CameraSessionDelegate: AnyObject {
+  /**
+   Called when there is a Runtime Error in the [CameraSession]
+   */
+  func onError(_ error: CameraError)
+  /**
+   Called when the [CameraSession] successfully initializes
+   */
+  func onSessionInitialized()
+  /**
+   Called for every frame (if video or frameProcessor is enabled)
+   */
+  func onFrame(sampleBuffer: CMSampleBuffer)
+  /**
+   Called whenever a QR/Barcode has been scanned. Only if the CodeScanner Output is enabled
+   */
+  func onCodeScanned(codes: [CameraSession.Code])
+}