CapacityScheduler incorrect User Group Mapping after leaf queue change

YARN-9879 and YARN-10198 introduced some major changes to user group mapping, and some of them unfortunately had some negative impact on the way mapping works.

In some cases incorrect PlacementContexts were created, where full queue path was passed as leaf queue name. This affects how the yarn cli app list displays the queues.

u:%user:%primary_group.%user mapping fails with an incorrect validation error when the %primary_group parent queue was a managed parent.

Group based rules in certain cases are mapped to root.[primary_group] rules, loosing the ability to create deeper structures.