Login with QR UI components (#6790)

* Display QR button on login screen if HS supports

* Create start screen

* Add build flag

* Connect start screen to the login

* QR display screen

* Move `LabelledDividerView` into separate file

* Show display QR screen on button tap

* Add swift concurreny to CameraAccessManager

* Introduce `QRLoginServiceProtocol`

* Use new service in screens

* Introduce scan QR code screen

* Remove hardcoded service availability

* Remove unnecessary import

* Add confirmation screen

* Add loading screen

* Fix ZXingObjc targets

* Add failure screen

* Add strings

* Various UI tweaks, navigation according to the service state

* Fix tests

* Add string for invalid QR error

* Add QR login service mode

Riot/Modules/Camera/CameraAccessManager.swift

@@ -48,6 +48,22 @@ final class CameraAccessManager {
             break
         }
     }
+
+    /// Checks and requests the camera access if needed. Returns `true` if granted, otherwise `false`.
+    func requestCameraAccessIfNeeded() async -> Bool {
+        let authStatus = AVCaptureDevice.authorizationStatus(for: .video)
+
+        switch authStatus {
+        case .authorized:
+            return true
+        case .notDetermined:
+            return await AVCaptureDevice.requestAccess(for: .video)
+        case .denied, .restricted:
+            return false
+        @unknown default:
+            return false
+        }
+    }
     
     // MARK: - Private