Introduce a feature flag for the new identity pinning violation notifications feature.

ElementX/Sources/Screens/RoomScreen/RoomScreenViewModel.swift

@@ -142,7 +142,9 @@ class RoomScreenViewModel: RoomScreenViewModelType, RoomScreenViewModelProtocol
         }
         .store(in: &cancellables)
         
-        let identityStatusChangesPublisher = roomProxy.identityStatusChangesPublisher.receive(on: DispatchQueue.main)
+        let identityStatusChangesPublisher = roomProxy.identityStatusChangesPublisher
+            .receive(on: DispatchQueue.main)
+            .filter { [weak self] _ in self?.appSettings.identityPinningViolationNotificationsEnabled ?? false }
         
         Task { [weak self] in
             for await changes in identityStatusChangesPublisher.values {

ElementX/Sources/Screens/Settings/DeveloperOptionsScreen/DeveloperOptionsScreenModels.swift

@@ -48,6 +48,7 @@ protocol DeveloperOptionsProtocol: AnyObject {
     var hideTimelineMedia: Bool { get set }
     var enableOnlySignedDeviceIsolationMode: Bool { get set }
     var elementCallBaseURLOverride: URL? { get set }
+    var identityPinningViolationNotificationsEnabled: Bool { get set }
 }
 
 extension AppSettings: DeveloperOptionsProtocol { }

ElementX/Sources/Screens/Settings/DeveloperOptionsScreen/View/DeveloperOptionsScreen.swift

@@ -49,6 +49,10 @@ struct DeveloperOptionsScreen: View {
                 Toggle(isOn: $context.hideTimelineMedia) {
                     Text("Hide image & video previews")
                 }
+                
+                Toggle(isOn: $context.identityPinningViolationNotificationsEnabled) {
+                    Text("Identity pinning violation notifications")
+                }
             }
             
             Section {