[Multi-staking] Create BSN registry

[jrwbabylonlab]

Start an RFC to propose the format and fields of the BSN registry for web service, some key fields includes:

• consumerId
• chainId
• chainName
• RPC URL
• Rewards Provider: Similar to the wallet providers
• Logo URL
• ...

https://babylonlabs.atlassian.net/wiki/spaces/BABYLON/pages/184713368/Reward+protocol+for+rollup+BSNs+formalisation+reference+design+and+extensions#Integration-with-the-BTC-staking-service-providers