feat(validator_node): new state store implementation using RocksDB

[mrnaveira]

NOTE: This PR is still a very early draft

Description

• New crate state_store_rocksdb with a RocksDB implementation of the consensus state store traits
• New validator node config option database_type to choose between "rocksdb" (default) and "sqlite"
• New (provisional) ValidatorNodeStateStore trait to make all VN creates independent of the database type. It's a provisional workaround as we ideally want to pass around values as something like Box<dyn StateStore>, but this requires some redesign of the StateStore (and related) traits.

Motivation and Context

Currently we only have a SQLite implementation of the VN state store. This is fine for development but something like RocksDB should result in a performance improvement.

How Has This Been Tested?

TBD

What process can a PR reviewer use to test or verify this change?

TBD

Breaking Changes

• None
• Requires data directory to be deleted
• Other - Please specify

[github-actions]

Test Results (CI)

0 tests   - 561   0 ✅  - 561   0s ⏱️ - 1h 24m 2s
0 suites  -  54   0 💤 ±  0 
0 files    -   1   0 ❌ ±  0 

Results for commit 489029a. ± Comparison against base commit a148dcb.

♻️ This comment has been updated with latest results.