* WIP first attempt to query variable
* regex issue repro demo
* Refresh variable on time range change if refresh specified
* Instantiate variable runner when updating query variable options
* Simplify runners getTarget interface
* Fix issue with variable ot being updated correctly after other variable changed
* Add templateSrv.replace compatibility with query variable
* QueryVariable: use datasource variable as source
* use proper format
* Make sure variables set is correctly updated when query variable errors
* Do not destruct scopedVars when using sceneGraph.interpolate in templateSrv
* Add support for Legacy variables (metricFindQuery)
* Review
* Fix lint
* Test: Add unit for datasource by variable
* test: Add unit for datasource as var
* query: delegate interpolation to datasourceSrv
* Cleanup
Co-authored-by: Ivan Ortega <ivanortegaalba@gmail.com>