Interleave the debug.log with the unit test log when run via ninja

Summary:
This diff adds the printtoconsole=1 option to the unit tests that are run via ninja.
Currently only boost content is part of the resulting log, which can be not enough to properly debug a failure. Now upon failure the output is much more verbose, but also more useful.

Test Plan:
Edit any test with BOOST_CHECK(false) and run that test via ninja:

ninja check-bitcoin-<test>

Check that stdout and test/log/<test_name>.log contain the debug.log content.

Reviewers: #bitcoin_abc, PiRK

Reviewed By: #bitcoin_abc, PiRK

Differential Revision: https://reviews.bitcoinabc.org/D16794