Excluding the basic reorgs hangle, we need a better bitcoind mock or a different testing approach to reach a higher code coverage. This is as far as it can get for the Responder at the moment
- Adds a PRG based on a hardcoded seed to make the tests reproducible (get_random_value_hex)
- Updates all the tests replacing urandom for get_random_value_hex
- Properly places misplaced bitcoin_cli in bitcoin_sim_tests
- Typos