[CMAKE] Rename the test wrapper util
Summary:
The test_wrapper.sh is currently used to run the unit tests, but is not
limited to this. This is in fact a generic wrapper for any runnable,
which silence the output unless it fails.
This diff renames the script to better reflect its intent.
Test Plan:
ninja check
Reviewers: #bitcoin_abc, deadalnix
Reviewed By: #bitcoin_abc, deadalnix
Subscribers: deadalnix
Differential Revision: https://reviews.bitcoinabc.org/D7469