Add periodic trace of GSM state

@karknu found a misbehavior with a small `docker-compose` `testnet`, and asked Consensus to dig in. If the node had been reporting its GSM state with some frequency automatically, then it would have taken us 5 minutes to create our feedback instead of a few hours (since we struggled to understand the `docker-compose` configuration mechanisms).

This Issue is to add two tracers to the GSM:

- trace the initial GSM state on start up
- every 10s or so, trace the current GSM state

These seem small enough to be in the node enabled by default --- at least in `ConsensusNode: GenesisMode`.

Start at ConsensusNode: GenesisMode and inspect how the node currently reports or traces GSM state, using the docker-compose testnet context described in the issue. Add startup and roughly 10-second GSM state traces, then verify both traces appear by running the relevant node or testnet setup.

Written by the indexing model from the issue text.