Switch off C++ tests from test.py discovery. With this change, test.py loses
the ability to directly see and run the C++ tests. Instead, it'll delegate all
things to the pytest.
Since boost, raft, unit, and ldap directories aren't executed by test.py,
suite.yaml files are renamed to test_config.yaml
to preserve the old way of test configuration and removing them from execution
by test.py
Before this patch boost test were visible by test.py and pytest. So if the
test.py will be invoked without test name, it will execute boost tests twice:
with test.py executor and with pytest executor. Depending on the test name
according executor will be used. For example, if test name is
test/boost/aggregate_fcts_test.cc it will be executed by pytest, but if the
boost/aggregate_fcts_test it will be executed by test.py executor.
