feat(protocol): decouple proof(s) verification from core protocol

[adaki2004]

This PR separates the proof verification logic.
SGX and other support can come late, and core protocol only sees bytes, no verifierId.

[dantaik]

For the core protocol, the proof shall be just a byte array, nothing else. Then the IProofVerifier contract should look like:

function verifyBlockProof(uint blockId, bytes calldata blockProof) external;

Later we can upgrade the implementation of IProofVerifier and use blockId to perform different verification tasks.