Prepare regression test covering database backup/restore

Regression test shall prepare a testnet HAF database, then shutdown the node and according to procedure described here https://gitlab.syncad.com/hive/haf#using-pg_dumppg_restore-to-backuprestore-a-haf-database perform a database backup.

Next another database shall be created (as usually its setup shall be done using setup_db.sh script) and SQL dump restored. After all, hived shall be resumed and i.e. continue production of few blocks. What important, during performing a backup hived state file should be preserved.