towards generic method polling and reposito;y; config settings to
filterevents/methods by account address; refactoring some stuff out of
repo and into converter; remove fetcher and instead call
blockchain's FetchContractData directly; finishing tests
* Separate Repository into multiple Repositories
* Use struct scan for transactions
* Use struct scan for blocks
* Remove unused block repo methods
* Update naming
* Rename / Cleanup repository related fields
* Add block categorization (is_final=)
* Add godo task for vulcanizeDB (Example of how everything could work together)
* Add unique constraint on block_number and node
* Add index on block_id for transactions_table
* Add node_id index on blocks table
* Sort transactions returned from FindBlock by tx_hash
* lowercase tx_to, tx_from like etherscan