QR Code Login Flow (#2767)

Co-authored-by: Hugh Nimmo-Smith <hughns@users.noreply.github.com>
Co-authored-by: Hugh Nimmo-Smith <hughns@element.io>

ElementX/Sources/Application/AppMediator.swift

@@ -14,6 +14,7 @@
 // limitations under the License.
 //
 
+import AVFoundation
 import UIKit
 
 class AppMediator: AppMediatorProtocol {
@@ -64,4 +65,22 @@ class AppMediator: AppMediatorProtocol {
     func setIdleTimerDisabled(_ disabled: Bool) {
         application.isIdleTimerDisabled = disabled
     }
+    
+    func requestAuthorizationIfNeeded() async -> Bool {
+        let status = AVCaptureDevice.authorizationStatus(for: .video)
+        
+        // Determine if the user previously authorized camera access.
+        if status == .authorized {
+            return true
+        }
+        
+        var isAuthorized = false
+        // If the system hasn't determined the user's authorization status,
+        // explicitly prompt them for approval.
+        if status == .notDetermined {
+            isAuthorized = await AVCaptureDevice.requestAccess(for: .video)
+        }
+        
+        return isAuthorized
+    }
 }