Merge topic 'GoogleTest-DISCOVERY_EXTRA_ARGS'

2dcba446e2 GoogleTest: Add DISCOVERY_EXTRA_ARGS to gtest_discover_tests()
f55f9fd5c1 Help: Mention TEST_LIST with gtest_discover_tests() can omit tests

Acked-by: Kitware Robot <kwrobot@kitware.com>
Tested-by: buildbot <buildbot@kitware.com>
Merge-request: !9856