fix test/unit_test.py and fix test/integration_test.py

`integration_test.py` uses now `blocks.get_tx_info2()`.
I added a mock for `bitcoinlib.rpc.getrawtransaction()`. This mock uses a specific table `raw_transactions` populated at the start from `listunspent.test.json` here https://github.com/JahPowerBit/counterpartyd/blob/multisig/test/util_test.py#L111 and for each new transaction here https://github.com/JahPowerBit/counterpartyd/blob/multisig/test/util_test.py#L90.
It's not very elegant, but for speed I used the same memory database to store `raw_transactions` table, so it appears on the dump generated when running a scenario.
Missing to fix `_test.py` by using the same mechanism as `integration_test.py`.