bfa9309ad6 Use COINBASE_MATURITY constant in functional tests. (Kiminuo)
525448df9d Move COINBASE_MATURITY from `feature_nulldummy` test to `blocktools`. (Kiminuo)
Pull request description:
`COINBASE_MATURITY` constant was added to `feature_nulldummy` test in #21373. This PR moves the constant to `blocktools.py` file and uses the constant in more tests as suggested [here](https://github.com/bitcoin/bitcoin/pull/21373#discussion_r605418462).
Edit: Goal of this PR is to replace integer constants with `COINBASE_MATURITY` but not necessarily in *all* cases because that would mean to read and fully understand all tests. That's out of my time constraints. Any reports where `COINBASE_MATURITY` should be used are welcome though!
ACKs for top commit:
theStack:
ACK bfa9309ad6🌇
Tree-SHA512: 01f04645f05a39028681f355cf3d42dd63ea3303f76d93c430e0fdce441934358a2d847a54e6068d61932f1b75e1d406f51859b057b3e4b569f7083915cb317f