One can not see in PB2 test logs which unit tests have been run
and passed.

This patchs adds an option --unit-tests-report to mtr which
include the ctest report in mtr output.  It will also turn on unit
testing if not explicitly turned off with --no-unit-tests or
equivalent.

In manual runs one can always look in the ctest.log file in mtr
vardir.

--unit-tests are replaced with --unit-tests-report in files under
mysql-test/collections/ to activate report in PB2.