[1.0-beta2 -> main] DeepMind: Add ID to ACCEPT_BLOCK_V2

[heifner]

ACCEPT_BLOCK_V2

ACCEPTED_BLOCK_V2 ${id} ${num} ${lib} ${blk} ${fd}
${id} => block id
${num} => block number
${lib} => Last irreversible block number
${blk} => signed_block in fc packed hex format
${fd} => finality_data_t in fc packed hex format

finality_data_t

struct finality_data_t {
   uint32_t     major_version{light_header_protocol_version_major};
   uint32_t     minor_version{light_header_protocol_version_minor};
   uint32_t     active_finalizer_policy_generation{0};
   uint32_t     final_on_strong_qc_block_num{0};
   digest_type  action_mroot{};
   digest_type  base_digest{};
   std::optional<finalizer_policy> proposed_finalizer_policy; // finalizer policy, if proposed in the block
};

   struct finalizer_policy {
      uint32_t                         generation = 0; ///< sequentially incrementing version number
      uint64_t                         threshold = 0;  ///< vote weight threshold to finalize blocks
      std::vector<finalizer_authority> finalizers;     ///< Instant Finality voter set
   }

   struct finalizer_authority {
      std::string  description;
      uint64_t     weight = 0;
      fc::crypto::blslib::bls_public_key  public_key;
   }

bls_public_key is affine non-montgomery base64url with prefix PUB_BLS_

Merges release/1.0-beta2 into main including #276

Resolves #261

[ericpassmore]

Note:start
group: STABILITY
category: INTERNALS
summary: Add explicit ID to ACCEPT_BLOCK_V2 to improve DeepMind support.
Note:end