Add RoomDetails for use (with RoomMemberDetails) in AvatarHeaderView. (#2490)

* Add RoomDetails and refactor AvatarHeaderView to use it.
* Remove old displayName property and use RoomDetails in the RoomDetailsScreenViewState

ElementX/Sources/Services/Room/RoomDetails.swift

@@ -0,0 +1,24 @@
+//
+// Copyright 2024 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 Foundation
+
+struct RoomDetails {
+    let id: String
+    let name: String?
+    let avatarURL: URL?
+    let canonicalAlias: String?
+}