lock.py: Add '--json-query' to allow complex search for --list/--brief

lock.py: Add '--json-query' to allow complex search for --list/--brief

--json-query <file> or --json-query <string> allows filtering search
results conveniently; the JSON must be a dictionary that is a subset
of the lock record to be matched.  The reason this was invented:
Find all VPSes on a particular vmhost:

teuthology-lock --list --all --json-query \
	'{"vm_host":{"name":"mira003.front.sepia.ceph.com"}}'

Signed-off-by: Dan Mick <dan.mick@redhat.com>