Added unit tests for NotificationManager (#376)

* NotificationManager tests

* More unit tests

* More tests, moved classes to separate files

* Removed warnings

* UserNotificationCenterProtocol as AnyObject

* Reverted back Package.resolved

UnitTests/Sources/NotificationManager/UNTextInputNotificationResponse+Creator.swift

@@ -0,0 +1,38 @@
+//
+// Copyright 2022 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 UserNotifications
+import XCTest
+
+extension UNTextInputNotificationResponse {
+    static func with(userInfo: [AnyHashable: Any], actionIdentifier: String = UNNotificationDefaultActionIdentifier) throws -> UNNotificationResponse {
+        let content = UNMutableNotificationContent()
+        content.userInfo = userInfo
+        let request = UNNotificationRequest(
+            identifier: "",
+            content: content,
+            trigger: nil
+        )
+        let archiver = MockCoder(requiringSecureCoding: false)
+        let notification = try XCTUnwrap(UNNotification(coder: archiver))
+        notification.setValue(request, forKey: "request")
+        
+        let response = try XCTUnwrap(UNTextInputNotificationResponse(coder: archiver))
+        response.setValue(notification, forKey: "notification")
+        response.setValue(actionIdentifier, forKey: "actionIdentifier")
+        return response
+    }
+}