* performance counters
* first cut of perf counters and system table fanout and a wire protocol
* significantly refactored prometheus support; removed statsd and exprvar
* removed node_id
* put dax subquery test back
* Change Translator.TranslateFieldIDs method to take a dax.TableKeyer
There are a bunch of other calls to the Translator interface methods
with currently take an `index string`, and those need to be converted to
dax.TableKeyer as well. But I need to review each call, because in at
least one place I noticed one being called with `result.Index` instead
of with the qtbl available. And I don't yet know how those could be
different.
Co-authored-by: Travis Turner <travis@molecula.com>
* Move batch.Importer interface to pilosa.Importer
In addition to moving the interface, it updates all the methods to use
dax.TableID (for example) intead of a string pilosa index name.
* Change unused onPremImporter methods to no-op.
onPremImporter is a wrapper around API which implements the Importer
interface. This is currently only used by sql3 running locally in standard
(i.e not "serverless") mode. Because sql3 always sets
`useShardTransactionalEndpoint = true`, There are several methods which this
implemtation of the Importer interface does not use, and therefore they
intentionally no-op.
