Garbage collection development update

Garbage collector for unreachable nodes of Merkle-Patricia tree

Last 2 weeks were mostly about iterating the design of GC so it can run and remove unreachable hashes from the DB on the disk without interrupting the operation of the node.

What we specifically aim for is:

  • concurrent running of the collection of all reachable hashes in the background
  • minimal time for removing unreachable hashes from DB and writing in reachable hashes DB - this step can’t run in the background

Actual development is close to finished, majority of the work remains in the test and verification area.

The state of the work can be followed here: https://github.com/aeternity/aeternity/commits/GH-2845-accounts-state-gc