Deprecate / remove channel_set_id from SendSatelliteCommandsRequest

[danada]

The intention of this field was to differentiate which channel set to use when commanding a satellite engaged with multiple ground stations at the same time. Since we are moving towards per-plan streams, the plan ID is enough information to determine which ground station to forward commands to.

Since this field was never implemented server-side and is marked as alpha, it should be relatively safe to remove without a deprecation step on the server.

stellarstation-api/api/src/main/proto/stellarstation/api/v1/stellarstation.proto

Line 272 in 782078c

string channel_set_id = 3;