CLPR: State Proofs On Consensus Nodes

The following critical tasks are required to construct state proofs on consensus nodes:
- [ ] Add the state proof protobuf.
- [ ] Add state proof utility classes: construction and verification.
- [ ] Capture latest BlockProof + State pairs (similar to `WorkingStateAccessor`)
- [ ] States can be queried for a Leaf + Merkle Proof to root hash.
- [ ] Unit test validation of the whole process, state proof construction and verification added to CI.

While the CLPR Prototype will exist on a separate branch `20111-clpr-prototype`, the above capability needs to be merged into main.

Start by reviewing the existing WorkingStateAccessor pattern and the separate 20111-clpr-prototype branch context. Identify the consensus-node entry points for BlockProof and State pairs, then trace how state queries expose a leaf and Merkle proof. Done means the protobuf, construction and verification utilities, pair capture and querying are implemented, with end-to-end unit validation running in CI.

Written by the indexing model from the issue text.