Render state items in the timeline and as the last message on the home screen. (#473)

* State events in the timeline WIP
* Implement membership change strings.
* Add other state event types and use in RoomSummaryProvider.

Co-authored-by: Stefan Ceriu <stefanc@matrix.org>

ElementX/Sources/Services/Timeline/TimelineItems/Items/Other/StateRoomTimelineItem.swift

@@ -0,0 +1,30 @@
+//
+// Copyright 2023 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 StateRoomTimelineItem: EventBasedTimelineItemProtocol, Identifiable, Hashable {
+    let id: String
+    let text: String
+    let timestamp: String
+    let groupState: TimelineItemGroupState
+    let isOutgoing: Bool
+    let isEditable: Bool
+    
+    var sender: TimelineItemSender
+    
+    var properties = RoomTimelineItemProperties()
+}