Add ability to auto-prune blockstore.db on startup

[suhasagg]

This PR adds an ability to auto-prune blockstore.db by copying latest N blocks from blockstore.db to a new blockstore.db, then archiving the original blockstore.db.

Issue: https://github.com/loomnetwork/loomchain/issues/1393

• [ ] I added unit tests for any code that added
• [ ] I updated the CHANGELOG.md
• [ ] All IP is original and not copied from another source
• [ ] I assign all copyright to Loom Network for the code in the pull request

[adyromantika]

The author is not recognized/whitelisted, so build will not happen.

[enlight]

rebuild sesame

[enlight]

rebuild sesame