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

RiotSwiftUI/Modules/Authentication/QRLogin/Display/Test/Unit/AuthenticationQRLoginDisplayViewModelTests.swift

@@ -0,0 +1,41 @@
+//
+// Copyright 2021 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import XCTest
+
+@testable import RiotSwiftUI
+
+class AuthenticationQRLoginDisplayViewModelTests: XCTestCase {
+    var viewModel: AuthenticationQRLoginDisplayViewModelProtocol!
+    var context: AuthenticationQRLoginDisplayViewModelType.Context!
+
+    override func setUpWithError() throws {
+        viewModel = AuthenticationQRLoginDisplayViewModel(qrLoginService: MockQRLoginService())
+        context = viewModel.context
+    }
+
+    func testCancel() {
+        var result: AuthenticationQRLoginDisplayViewModelResult?
+
+        viewModel.callback = { callbackResult in
+            result = callbackResult
+        }
+
+        context.send(viewAction: .cancel)
+
+        XCTAssertEqual(result, .cancel)
+    }
+}