[services] Tunnelbroker - Removing of 'sessionID' from 'MessageToTunnelbroker'

Summary:
This diff removes the sessionID from the messages incoming to the Tunnelbroker. The purpose of this field was client authentication by providing the sessionID from the client. This method is not efficient because we will repeat the sessionID on every message instead of providing it once when the stream is opening.

Instead of repeating the sessionID on every message, we should use a gRPC canonical way for the authentication which is about using the context metadata. The full context is available in the Linear task.

Linear task: ENG-1359

Test Plan: Services were successfully built, protobuf file was successfully compiled.

Reviewers: jon, tomek, ashoat

Reviewed By: tomek, ashoat

Subscribers: ashoat, tomek, atul, abosh

Differential Revision: https://phab.comm.dev/D5525