The latency metrics holds a single counter, so there is no need to add
the total_latency to the url it is pointed to.
Removing it, can shorten the url in the API definitions.
LatencyMetrics
This import the implementation of CASClientRequestMetrics
ClientRequestMetrics and LatencyMetrics with modification to use the
APIMetrics with a given URL.
The Metrics where added to keep the same naming of of the MBean as they
are in Origin.
Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>