Refactor the JoinRoom screen to take advantage of newer APIs and support more joinRule/membership combinations (i.e. invite required, restricted, banned) (#3685)

- expose the full RoomPreview and RoomMembershipDetails through their own proxies
- implement standard mocks for all the different combinations
- converge on a single room info provider
- rebuild all the previews
- prioritise the preview data over the room one.

ElementX/Sources/Services/Client/ClientProxy.swift

@@ -516,11 +516,10 @@ class ClientProxy: ClientProxyProtocol {
         return await buildRoomForIdentifier(identifier)
     }
     
-    func roomPreviewForIdentifier(_ identifier: String, via: [String]) async -> Result<RoomPreviewDetails, ClientProxyError> {
+    func roomPreviewForIdentifier(_ identifier: String, via: [String]) async -> Result<RoomPreviewProxyProtocol, ClientProxyError> {
         do {
             let roomPreview = try await client.getRoomPreviewFromRoomId(roomId: identifier, viaServers: via)
-            let roomPreviewInfo = try roomPreview.info()
-            return .success(.init(roomPreviewInfo))
+            return try .success(RoomPreviewProxy(roomPreview: roomPreview))
         } catch let error as ClientError where error.code == .forbidden {
             return .failure(.roomPreviewIsPrivate)
         } catch {
@@ -1155,40 +1154,3 @@ private class SendQueueRoomErrorListenerProxy: SendQueueRoomErrorListener {
         onErrorClosure(roomId, error)
     }
 }
-
-private extension RoomPreviewDetails {
-    init(_ roomPreviewInfo: RoomPreviewInfo) {
-        self = RoomPreviewDetails(roomID: roomPreviewInfo.roomId,
-                                  name: roomPreviewInfo.name,
-                                  canonicalAlias: roomPreviewInfo.canonicalAlias,
-                                  topic: roomPreviewInfo.topic,
-                                  avatarURL: roomPreviewInfo.avatarUrl.flatMap(URL.init(string:)),
-                                  memberCount: UInt(roomPreviewInfo.numJoinedMembers),
-                                  isHistoryWorldReadable: roomPreviewInfo.isHistoryWorldReadable ?? false,
-                                  isJoined: roomPreviewInfo.membership == .joined,
-                                  isInvited: roomPreviewInfo.membership == .invited,
-                                  isPublic: roomPreviewInfo.isPublic,
-                                  canKnock: roomPreviewInfo.canKnock)
-    }
-}
-
-private extension RoomPreviewInfo {
-    var canKnock: Bool {
-        switch joinRule {
-        case .knock, .knockRestricted:
-            return true
-        default:
-            return false
-        }
-    }
-    
-    var isPublic: Bool {
-        switch joinRule {
-        // for restricted rooms we want to show optimistically that the we may be able to join the room
-        case .public, .restricted:
-            return true
-        default:
-            return false
-        }
-    }
-}