Update Elasticsearch monitoring for 1.0

Most of the monitoring APIs changes a bit so we tweak them to work again.
Biggest change is moving the search groups into the main api nodes stats
call which means they are per node rather than the same across the whole
cluster.  It'll be nice to see how much of each group each node is working.

Bug: 60979
Change-Id: I16ddc51cb85521762855ed0f3f4ab7c5f17c5372