* tsdb: add support for setting debug flag of tsdb query
* alerting: adds debug flag in eval context
Debug flag is set when testing an alert rule and this debug
flag is used to return more debug information in test aler rule
response. This debug flag is also provided to tsdb queries so
datasources can optionally add support for returning additional
debug data
* alerting: improve test alert rule ui
Adds buttons for expand/collapse json and copy json to clipboard,
very similar to how the query inspector works.
* elasticsearch: implement support for tsdb query debug flag
* elasticsearch: embedding client response in struct
* alerting: return proper query model when testing rule
Removes moment dependency.
Adds response parser tests (based on frontend tests).
Adds time series query tests (based on frontend tests).
Fixes various issues related to response parsing and building search request queries.
Added support for extended stats metrics and geo hash grid aggregations.
