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/example/src/CameraPage.tsx

@@ -47,7 +47,12 @@ export function CameraPage({ navigation }: Props): React.ReactElement {
 
   // camera device settings
   const [preferredDevice] = usePreferredCameraDevice()
-  const device = useCameraDevice(cameraPosition)
+  let device = useCameraDevice(cameraPosition)
+
+  if (preferredDevice != null && preferredDevice.position === cameraPosition) {
+    // override default device with the one selected by the user in settings
+    device = preferredDevice
+  }
 
   const [targetFps, setTargetFps] = useState(60)
 
@@ -172,7 +177,7 @@ export function CameraPage({ navigation }: Props): React.ReactElement {
               <ReanimatedCamera
                 ref={camera}
                 style={StyleSheet.absoluteFill}
-                device={preferredDevice ?? device}
+                device={device}
                 format={format}
                 fps={fps}
                 hdr={enableHdr}