[Chronik] Add various block stats to BlockInfo protobuf message

Summary:
Provide block stats in the BlockInfo protobuf message. This applies to both the /block and /blocks endpoint.

Depends on D13849 and D13850.

Test Plan: ninja check-functional

Reviewers: Fabien, #bitcoin_abc, PiRK

Reviewed By: #bitcoin_abc, PiRK

Differential Revision: https://reviews.bitcoinabc.org/D13852