Merge PR #52652 into main

* refs/pull/52652/head:
	PendingReleaseNotes: add note about new mdlog trimming configurations
	mds: drive mdlog trimming via a separate thread
	mds: allow runtime modification of mdlog trimming configuration
	mds: remove a bunch of heuristics from MDLog::trim()
	mds: add mdlog trimming threshold and decay counter

Reviewed-by: Leonid Usov <leonid.usov@ibm.com>