Problem: pruning is not supported in current versiondb PR

https://github.com/facebook/rocksdb/wiki/User-defined-Timestamp-%28Experimental%29#compaction-and-garbage-collection-gc

There's some support for that in rocksdb, just need to setup configuration.

Start with the linked RocksDB wiki section on user-defined timestamps, compaction, and garbage collection, then trace Cronos's VersionDB configuration and pruning entry points. Done means the current VersionDB setup supports pruning without breaking its existing storage behavior; the issue does not name specific files or tests.

Written by the indexing model from the issue text.