chore: update to BTC multisig delegation

[RafilxTenfen]

• Modified BTC staker to use staker address instead of public key
• Update staker address of e2e test to use the address of the signer
• CLI tested at https://github.com/babylonchain/babylon-deployment/pull/96, the BTC staker Babylon key inside the config needs to be the staker

Merge after https://github.com/babylonchain/babylon/pull/657

[RafilxTenfen]

delegationDataToMsg

good catch, removed signer from func in https://github.com/babylonchain/btc-staker/pull/167/commits/8fa42ef1c59e7a8d716f89c921887c1ea8a2f53c