Add message type for Message and change data type enum vals
Add message type for Message and change data type enum vals

Possible values for message type:
* control - control message (create_group, leave_group, list_contacts, etc...)
* message - instant text message
* file    - if sent from client data is binary content of the file
            if sent from server data is file token

Use same values to map websocket types for text and binary messages

itsankoff/gotcha,itsankoff/gotcha