feat(node): validator reward skeleton implementation

[cryptoAtwill]

This PR extends #1162 with the following:

• Implemented the validator reward distribution flow in the parent subnet. Instead of adding directly to the subnet storage, this PR uses library and facet to make reward distribution more modular.
• Added a metadata field to validator summary for extra data required.
• Added ValidatorActivityTracker trait fendermint so that the implementation can decide how to track validator's activity.
• Implemented a solidity contract based ValidatorActivityTracker, only contract is implemented at the moment.

Todos:

• [x] Gather initial feedbacks on this approach.
• [x] Adding integration for ValidatorActivityTracker and solidity contracts.
• [ ] Tests

[raulk]

Integrated into https://github.com/consensus-shipyard/ipc/pull/1181.