Hide the unread dot after previewing an invite. (#3800)

* Hide the unread dot when previewing an invite.

* Remove an invited room ID when accepting/rejecting.

* Remove the unread badge from knocked room cells.

* Update snapshots.

* Address PR comments.

Refactor KnockRequestType to JoinRequestType.

ElementX/Sources/Mocks/InvitedRoomProxyMock.swift

@@ -25,6 +25,8 @@ extension InvitedRoomProxyMock {
         id = configuration.id
         inviter = configuration.inviter
         info = RoomInfoProxy(roomInfo: .init(configuration))
+        
+        rejectInvitationReturnValue = .success(())
     }
 }