SSE: DSNode to update result with names to make each value identifiable by labels (only Graphite and TestData) (#71246)

* introduce a function checkIfSeriesNeedToBeFixed to scan all value fields in the response and provide a function that updates Series so they can be uniquely identifiable. Only Graphite and TestData are checked.

* update `convertDataFramesToResults` to run this function and provide it to WideToMany
* update WideToMany to run the fix function if it is not nil

pkg/services/ngalert/backtesting/eval_data.go

@@ -21,7 +21,7 @@ type dataEvaluator struct {
 }
 
 func newDataEvaluator(refID string, frame *data.Frame) (*dataEvaluator, error) {
-	series, err := expr.WideToMany(frame)
+	series, err := expr.WideToMany(frame, nil)
 	if err != nil {
 		return nil, err
 	}