V2Tool ‘server mode’

The V2Tool should read its server configuration information from a configuration file and start the GRPC server following it.
Every time a client (shipper, inputs, etc) connects to the server, the server will send corresponding configuration in the same way it would if it had started the binary.

Clients connecting/disconnecting should be handled gracefully, there should be no need to re-start the V2Tool once it’s running.

Once the server is started, it should log the connection information: host, port, T;S status (enabled/disabled), connection token (it’s for testing, it’s not meant to be secure). Logging the token might be a point for further discussion.

Start by locating the V2Tool server-mode entry point and the GRPC server setup. Read how the binary currently supplies configuration to clients, then determine how configuration-file loading and client connection handling should fit together. Done means the server starts from its configuration, reports its connection details, and handles clients without a restart.

Written by the indexing model from the issue text.