Knocking feature polishing part 2 (#3738)

* improved implementation of the unknown state

* forget button in the banned state

* error handling for forbidden access

* added the forget function

fixed DMs, and updated preview tests

* removed banned room proxy

* code polishing and test improvement

ElementX/Sources/Mocks/Generated/GeneratedMocks.swift

@@ -13393,6 +13393,70 @@ class RoomPreviewProxyMock: RoomPreviewProxyProtocol, @unchecked Sendable {
     var underlyingOwnMembershipDetails: RoomMembershipDetailsProxyProtocol?
     var ownMembershipDetailsClosure: (() async -> RoomMembershipDetailsProxyProtocol?)?
 
+    //MARK: - forgetRoom
+
+    var forgetRoomUnderlyingCallsCount = 0
+    var forgetRoomCallsCount: Int {
+        get {
+            if Thread.isMainThread {
+                return forgetRoomUnderlyingCallsCount
+            } else {
+                var returnValue: Int? = nil
+                DispatchQueue.main.sync {
+                    returnValue = forgetRoomUnderlyingCallsCount
+                }
+
+                return returnValue!
+            }
+        }
+        set {
+            if Thread.isMainThread {
+                forgetRoomUnderlyingCallsCount = newValue
+            } else {
+                DispatchQueue.main.sync {
+                    forgetRoomUnderlyingCallsCount = newValue
+                }
+            }
+        }
+    }
+    var forgetRoomCalled: Bool {
+        return forgetRoomCallsCount > 0
+    }
+
+    var forgetRoomUnderlyingReturnValue: Result<Void, RoomProxyError>!
+    var forgetRoomReturnValue: Result<Void, RoomProxyError>! {
+        get {
+            if Thread.isMainThread {
+                return forgetRoomUnderlyingReturnValue
+            } else {
+                var returnValue: Result<Void, RoomProxyError>? = nil
+                DispatchQueue.main.sync {
+                    returnValue = forgetRoomUnderlyingReturnValue
+                }
+
+                return returnValue!
+            }
+        }
+        set {
+            if Thread.isMainThread {
+                forgetRoomUnderlyingReturnValue = newValue
+            } else {
+                DispatchQueue.main.sync {
+                    forgetRoomUnderlyingReturnValue = newValue
+                }
+            }
+        }
+    }
+    var forgetRoomClosure: (() async -> Result<Void, RoomProxyError>)?
+
+    func forgetRoom() async -> Result<Void, RoomProxyError> {
+        forgetRoomCallsCount += 1
+        if let forgetRoomClosure = forgetRoomClosure {
+            return await forgetRoomClosure()
+        } else {
+            return forgetRoomReturnValue
+        }
+    }
 }
 class RoomProxyMock: RoomProxyProtocol, @unchecked Sendable {
     var id: String {