Proto: update aggregate operations result

What

Providing individual consensus_power for each delegate in aggregate operations results.

Why

To make it easier to understand/process for users and external tools providers.

How

Manually testing the MR

tezt --verbose --file tezt/tests/baker_test.ml --title 'Alpha: Attestations aggregation on reproposal'

at the end, one should see the list of consensus operations holding aggregate with the following form :

 [ { "protocol": "ProtoALphaALphaALphaALphaALphaALphaALphaALphaDdp3zK",
     "chain_id": "NetXdQprcVkpaWU",
     "hash": "oo4x52aEzh5g6NpzeU48PfUdtNJL692Kxa7Un6pkjh5ottzRJCR",
     "branch": "BLuBuQPYq1b5eNz12e9EHKJYAVt4uiNWy88vLeSEnAumPK8Bk5E",
     "contents":
       [ { "kind": "attestations_aggregate",
           "consensus_content":
             { "level": 9, "round": 1,
               "block_payload_hash":
                 "vh2t7QtMUie8e63tNNWwxfMVQ7rzkuRwwcGXKHhyskzSWhnWPFXq" },
           "committee":
             [ { "slot": 1, "dal_attestation": "65535" },
               { "slot": 12, "dal_attestation": "65535" },
               { "slot": 38, "dal_attestation": "65535" } ],
           "metadata":
             { "committee":
                 [ { "delegate": "tz1KqTpEZ7Yob7QbPE4Hy4Wo8fHG8LhKxZSx",
                     "consensus_pkh": "tz4Ga1SRnNHQQqKYNSCjbztn9hymbRLJ1YnA",
                     "consensus_power": 46 },
                   { "delegate": "tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN",
                     "consensus_pkh": "tz4BifWYqDkfTwssqdQRJhrdZfE2jsr6a9FZ",
                     "consensus_power": 55 },
                   { "delegate": "tz1faswCTDciRzE4oJ9jn2Vm2dvjeyA9fUzU",
                     "consensus_pkh": "tz4XZQpy8RjqAu1VpftT2qc448eSuuYUjTLz",
                     "consensus_power": 30 } ], "total_consensus_power": 131 } } ],
     "signature":
       "BLsigANWbWKvyNXNPkgvgGCH3mPdStDMaPq3WuadKmWo64x9oAdtNLJqKZREDTjVyeeP9uMGgkBJ1rir8vSAu1yd5WoUAz3FhktZMPN8GrDkUKohPhgF3RDrDgiyZ1WmFm4hPHe47rpSLC" },
   { "protocol": "ProtoALphaALphaALphaALphaALphaALphaALphaALphaDdp3zK",
     "chain_id": "NetXdQprcVkpaWU",
     "hash": "ooNPMd4JbZ8MadCSSMtFYngay3VtsKxPyzpsqsqSKaTUzT3bPyw",
     "branch": "BMawSqKqUbb4uuXky1hRNayg48LEJHSmYRn15oWrkNNrHR16Pcp",
     "contents":
       [ { "kind": "preattestations_aggregate",
           "consensus_content":
             { "level": 10, "round": 8,
               "block_payload_hash":
                 "vh1y169zRdN7EzZTvj1ygTVgbT718SxTGbNdGe5WZnPooKEALreZ" },
           "committee": [ 1, 4 ],
           "metadata":
             { "committee":
                 [ { "delegate": "tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN",
                     "consensus_pkh": "tz4BifWYqDkfTwssqdQRJhrdZfE2jsr6a9FZ",
                     "consensus_power": 39 },
                   { "delegate": "tz1KqTpEZ7Yob7QbPE4Hy4Wo8fHG8LhKxZSx",
                     "consensus_pkh": "tz4Ga1SRnNHQQqKYNSCjbztn9hymbRLJ1YnA",
                     "consensus_power": 36 } ], "total_consensus_power": 75 } } ],
     "signature":
       "BLsigAMDb5nUEn48JTFJe56wR1Aj8WTN4KYuoHZd9fBDHmFQ1rYyW4HVQe3puWMdVVgjizCRNYPsddwqWdDds3SQz8WgUCgcU3tdiBnqB8MvosKMbKgN7DJ8dtFYW5RrPukw96uYGi97vk" },

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR