Transformations: Add support for dashboard variable in limit, sort by, filter by value, heatmap and histogram (#75372)

* variables for filterforvalue

* use datalinkinput for basic matcher

* fix user select issue

* heatmap transformation variable interpolation

* clean code

* interpolate sort by

* add options interpolation in histogram transformation

* interpolation for limit

* Add suggestions UI to Filter by data value Transformation

Co-authored-by: oscarkilhed <oscar.kilhed@grafana.com>

* add validation for number/variable fields

* Add variables to add field from calculation

* Add validator to limit transformation

* Refactor validator

* Refactor suggestionInput styles

* Add variable support in heatmap calculate options to be in sync with tranform

* Refactor SuggestionsInput

* Fix histogram, limit and filter by value matchers

* clean up weird state ref

* Only interpolate when the feature toggle is set

* Add feature toggle to ui

* Fix number of variable test

* Fix issue with characters typed after opening suggestions still remains after selecting a suggestion

* Clean up from review

* Add more tests for numberOrVariableValidator

---------

Co-authored-by: Victor Marin <victor.marin@grafana.com>

pkg/services/featuremgmt/registry.go

@@ -823,5 +823,12 @@ var (
 			FrontendOnly: false,
 			Owner:        hostedGrafanaTeam,
 		},
+		{
+			Name:         "transformationsVariableSupport",
+			Description:  "Allows using variables in transformations",
+			FrontendOnly: true,
+			Stage:        FeatureStageExperimental,
+			Owner:        grafanaBiSquad,
+		},
 	}
 )

pkg/services/featuremgmt/toggles_gen.csv

@@ -117,3 +117,4 @@ cloudWatchWildCardDimensionValues,GA,@grafana/aws-datasources,false,false,false,
 externalServiceAccounts,experimental,@grafana/grafana-authnz-team,true,false,false,false
 alertingModifiedExport,experimental,@grafana/alerting-squad,false,false,false,false
 enableNativeHTTPHistogram,experimental,@grafana/hosted-grafana-team,false,false,false,false
+transformationsVariableSupport,experimental,@grafana/grafana-bi-squad,false,false,false,true

pkg/services/featuremgmt/toggles_gen.go

@@ -478,4 +478,8 @@ const (
 	// FlagEnableNativeHTTPHistogram
 	// Enables native HTTP Histograms
 	FlagEnableNativeHTTPHistogram = "enableNativeHTTPHistogram"
+
+	// FlagTransformationsVariableSupport
+	// Allows using variables in transformations
+	FlagTransformationsVariableSupport = "transformationsVariableSupport"
 )