[backport] [CMAKE] Increase the unit test verbosity to test_suite
Summary: Default is error, this bumps to test_suite: https://www.boost.org/doc/libs/1_64_0/libs/test/doc/html/boost_test/utf_reference/rt_param_reference/log_level.html
Test Plan: ninja check Cause a failure in a unit test and check the output is more verbose.
Reviewers: #bitcoin_abc, deadalnix
Reviewed By: #bitcoin_abc, deadalnix
Differential Revision: https://reviews.bitcoinabc.org/D5882