Merge topic 'ctest-cleanup'

0432b921ae cmCTestMultiProcessHandler: Inline removal of pending test as it starts
b17c732e88 cmCTestMultiProcessHandler: Clarify role of StartTestProcess
0950acb337 cmCTestMultiProcessHandler: Manage concurrency slots with other resources
697900da29 cmCTestMultiProcessHandler: Manage affinity assignments with other resources

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: buildbot <buildbot@kitware.com>
Merge-request: !8999