* op-supervisor: Introduce head tracker

* op-supervisor: Move log db to subpackage of db.

* op-supervisor: Route all updates through a common db that can track heads

* op-supervisor: Remove unused error.

* op-supervisor: Remove operations - it fits into a later PR.

* op-supervisor: Fix semgrep

* op-supervisor: Move resuming databases into ChainsDB so it can later update the chain heads too.

Ensures the database is rewound to the point where it can retry storing the logs for the block rather than having some logs already exist.

* op-supervisor: Introduce pipeline concept and stage to handle all blocks on head update

* op-supervisor: Simplify to just call a block processor directly

* op-supervisor: Simplify further to remove pipeline entirely and hook up processor

* op-supervisor: Separate out and test the head update callback.

* op-supervisor: Fetch receipts for each block