This PR adds persistence for peer feature flags when updating metadata, including equality checks, gRPC extraction, and corresponding unit tests.
- Introduce a new `Flags` struct with `isEqual` and incorporate it into `PeerSystemMeta`.
- Update `UpdateMetaIfNew` logic to consider flag changes.
- Extend gRPC server’s `extractPeerMeta` to populate `Flags` and add tests for `Flags.isEqual`.