add NSE sources to EX project to easily implement mocking and allow the code to be unit tested

NSE/Sources/NSEUserSession.swift

@@ -9,10 +9,19 @@
 import Foundation
 import MatrixRustSDK
 
-final class NSEUserSession {
-    let sessionDirectories: SessionDirectories
-    let appSettings: CommonSettingsProtocol
+// sourcery: AutoMockable
+protocol NSEUserSessionProtocol {
+    var inviteAvatarsVisibility: InviteAvatars { get async }
+    var mediaPreviewVisibility: MediaPreviews { get async }
+    var threadsEnabled: Bool { get }
     
+    func notificationItemProxy(roomID: String, eventID: String) async -> NotificationItemProxyProtocol?
+    func roomForIdentifier(_ roomID: String) -> Room?
+}
+
+final class NSEUserSession: NSEUserSessionProtocol {
+    private let sessionDirectories: SessionDirectories
+    private let appSettings: CommonSettingsProtocol
     private let baseClient: Client
     private let notificationClient: NotificationClient
     private let userID: String
@@ -42,6 +51,10 @@ final class NSEUserSession {
             }
         }
     }
+    
+    var threadsEnabled: Bool {
+        appSettings.threadsEnabled
+    }
 
     init(credentials: KeychainCredentials,
          roomID: String,