zoneconcierge: replace chain ID with client ID for consumers

[SebastianElvis]

Subsumes #22

---

Fixes https://github.com/babylonlabs-io/pm/issues/12

This PR replaces the chain ID with the client ID for consumers in the BTC timestamping protocol. This is in line with the IBC security model where each IBC light client corresponds to a chain, and with the BTC staking integration implementation.

The PR includes:

• renaming all chain ID to consumer ID, same as BTC staking integration does
• using client ID to identify {epoch, finalised} chain info
• changing all queries, fuzz tests, e2e tests, and doc accordingly

TODO before merging the PR:

• wait until @gitferry verifies we can do software upgrade with empty DB and updated DB schema

Plan after the PR:

• Fixing compatiblity with BE/FE (need arch decisions here)

[KonradStaniec]

Looks good!