qa/tests: test if unresponsive MDS client with no caps is evicted directly

qa/tests: test if unresponsive MDS client with no caps is evicted directly

Test if an unresponsive MDS client session holding no caps is evicted
directly at session_autoclose without being marked as stale at
session_timeout.

Signed-off-by: Rishabh Dave <ridave@redhat.com>
(cherry picked from commit 80152465b565519e7d5d83a9ddbcc96d805470bf)

Conflicts:
	qa/tasks/cephfs/test_client_recovery.py
- no "test_abort_conn()" method in mimic, since "client: introduce
  ceph_abort_conn() PR#22543" is not being backported