Refactored the validation of ClientDetails out of ClientAdminEndpoints
so it can be used by both IdentityZoneEndpoints and ClientAdminEndpoints
Appending identity_zone_id = ... to all filters in user queries. It was
being missed in retrieveAll().

https://www.pivotaltracker.com/story/show/83974104
[#83974104]
using a count(*) for getTotalUsers() if the dao supports it.

https://www.pivotaltracker.com/story/show/83974104
[#83974104]
Added ResourceMonitor to provide JMX monitoring enpoints with an
accurate count of object in persistence. Brought back tests for
JdbcQueryableClientDetailsService.