Notification Handler to handle notifications in foreground (#837)

* changed how the notifications are handled

* local notifications can be decrypted and shown!

* Improved the handling for the mock and for the normal messages

* Avatar images are also displayed

* pr ready, commented some code that is not supposed to be releaaed yet, adjusted some tests and added some source code in the targets

* fixing some swiftlint complaints and removed an unused function

* better swiftlint disable

* addressing PR comments

ElementX/Sources/Application/AppCoordinator.swift

@@ -288,7 +288,7 @@ class AppCoordinator: AppCoordinatorProtocol {
         
         userSessionFlowCoordinator = nil
 
-        notificationManager.setClientProxy(nil)
+        notificationManager.setUserSession(nil)
     }
     
     private func presentSplashScreen(isSoftLogout: Bool = false) {
@@ -302,7 +302,7 @@ class AppCoordinator: AppCoordinatorProtocol {
     }
 
     private func configureNotificationManager() {
-        notificationManager.setClientProxy(userSession.clientProxy)
+        notificationManager.setUserSession(userSession)
         notificationManager.requestAuthorization()
 
         if let appDelegate = AppDelegate.shared {