Lock the Link New Device flow to portrait and improve Cancel/Try Again handling. (#5094)

* Lock the LinkNewDeviceScreen to portrait.

* Add cancel buttons to the QR Code errors and handle cancel/startOver correctly.

* Use the shared QRCodeErrorView in the LinkNewDeviceScreen.

* Clarify the different QR Error/ErrorStates a bit more.

* Update snapshots.

ElementX/Sources/Services/Authentication/AuthenticationService.swift

@@ -262,7 +262,7 @@ private extension HumanQrLoginError {
         case .Expired, .NotFound: // The most likely cause of a .NotFound is that the rendezvous session expired on the server side
             .qrCodeError(.expired)
         case .SlidingSyncNotAvailable:
-            .qrCodeError(.deviceNotSupported)
+            .qrCodeError(.slidingSyncNotAvailable)
         case .OtherDeviceNotSignedIn:
             .qrCodeError(.deviceNotSignedIn)
         case .Unknown, .OidcMetadataInvalid, .CheckCodeAlreadySent, .CheckCodeCannotBeSent:

ElementX/Sources/Services/Authentication/AuthenticationServiceProtocol.swift

@@ -103,7 +103,7 @@ enum QRCodeLoginError: Error, Equatable {
     case declined
     case linkingNotSupported
     case expired
-    case deviceNotSupported
+    case slidingSyncNotAvailable
     case deviceNotSignedIn
     case deviceAlreadySignedIn
     case unknown