What

Add Attestation_aggregate as a new consensus operation and provide some implementations when required.

Why

Many updates involved, I splitted everything in separate commits to ease reviewing.

Commits will be squashed before merging to maintain the "each commit should compile" tezos invariant.

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

Edited Nov 13, 2024 by Adam