Solr metrics missing in DSE 6.8

[jeromatron]

With DSE 5.1.14 with DSE Search enabled, the Search Query Metrics section has metrics getting reported. However these same metrics have no data for DSE 6.8. This applies to most of the search cluster dashboard panels. Most have data, though some have fake data even on 5.1.

In DSE 6.8, the dse_solr* metrics don't seem to exist (com.datastax.bdp.search in svc monitor regex).

When curling the metrics endpoint, and grepping solr, you can only see metric names like:
org.apache.cassandra.metrics.thread_pools.<various>tasks.internal.tpc<all | other>_solr_indexing

[bhisey]

Hi Jeremy,

Updated, DSE 6.x graphs and comments through the following pull request These needs to be verified,
#30