[release/8.0-staging] improve distribute_free_regions (#115023)

* new-dfr in one commit

* fixes for decommitting large+huge and comments

* only age regions during BGC

* fix age_all_region_kinds condition.

* fixing merge conflict.

* fix merge issues.

* PR Feedback

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Co-authored-by: Mark Plesko <markples@microsoft.com>

Author: mangod9