Make default test suite work without synchronized daemon

[MrNaif2018]

Currently, those 2 tests (and potentially more):
tests/coins/btc/test_without_wallet.py::test_get_tx

tests/coins/btc/test_without_wallet.py::test_get_address

Rely on real-time data, which means we have to wait for daemon sync. We need to check if it's possible to move some of the tests to regtest test suite, so that regular runs are fast