CloudWatch: Refactor to extract DataQuery grouping by region out of request parsing (#57392)

* CloudWatch: Extract request parsing grouping by region from ParseQueries

* Rename ParseQueries to ParseMetricDataQueries

pkg/tsdb/cloudwatch/time_series_query.go

@@ -31,15 +31,23 @@ func (e *cloudWatchExecutor) executeTimeSeriesQuery(ctx context.Context, req *ba
 		return nil, fmt.Errorf("invalid time range: start time must be before end time")
 	}
 
-	requestQueriesByRegion, err := models.ParseQueries(req.Queries, startTime, endTime, e.features.IsEnabled(featuremgmt.FlagCloudWatchDynamicLabels))
+	requestQueries, err := models.ParseMetricDataQueries(req.Queries, startTime, endTime, e.features.IsEnabled(featuremgmt.FlagCloudWatchDynamicLabels))
 	if err != nil {
 		return nil, err
 	}
 
-	if len(requestQueriesByRegion) == 0 {
+	if len(requestQueries) == 0 {
 		return backend.NewQueryDataResponse(), nil
 	}
 
+	requestQueriesByRegion := make(map[string][]*models.CloudWatchQuery)
+	for _, query := range requestQueries {
+		if _, exist := requestQueriesByRegion[query.Region]; !exist {
+			requestQueriesByRegion[query.Region] = []*models.CloudWatchQuery{}
+		}
+		requestQueriesByRegion[query.Region] = append(requestQueriesByRegion[query.Region], query)
+	}
+
 	resultChan := make(chan *responseWrapper, len(req.Queries))
 	eg, ectx := errgroup.WithContext(ctx)
 	for r, q := range requestQueriesByRegion {