Fixed auto scale chat window / admin tool window when assign other member as manager. (ChatScreen)

Implemented clear canvas function.
Modified initialization of 3 controllers in server.

Issue:
_ still cannot load canvas which has text on it
_ text insert is not proper functional in the first insertion. after a shape is input, text insertion function starts to work properly.
_ added serializableImage class but don't know how it works and how to implement it.