Non-decryptable timeline items and debug menu (#300)

* Fixes #292 - Added a timeline item context menu option for printing and showing their debug description
* Fixes #291 - Add support for non-decryptable timeline items

ElementX/Sources/Services/Timeline/TimelineItems/Items/EncryptedRoomTimelineItem.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 UIKit
+
+struct EncryptedRoomTimelineItem: EventBasedTimelineItemProtocol, Identifiable, Equatable {
+    enum EncryptionType: Equatable {
+        case megolmV1AesSha2(sessionId: String)
+        case olmV1Curve25519AesSha2(senderKey: String)
+        case unknown
+    }
+    
+    let id: String
+    let text: String
+    let encryptionType: EncryptionType
+    let timestamp: String
+    let inGroupState: TimelineItemInGroupState
+    let isOutgoing: Bool
+    
+    let senderId: String
+    var senderDisplayName: String?
+    var senderAvatar: UIImage?
+    
+    var properties = RoomTimelineItemProperties()
+}