GP Desktop and Cloud real-time update protocol v1

[dbarashev]

In the first version of the RT update protocol we will assume that all clients are up to date with the server, and there are no clients who are lagging behind.

The protocol works as follows:

• the client accumulates insert and update statements produced during a single undoable edit and sends them via the web socket to the server
• the server applies the updates and in case of success broadcasts them to all other clients