CloudWatch: Remove HighResolution toggle since it's not being used (#20440)

* Remove highres flag since it's not being used

* Remove not used code. Init id field correctly

* Fix broken tests

* Remove GMS related calculations

* Rename period field

* Add breaking changes to changelog. Also update upgrading docs

* Update snapshot

* Update docs after feedback

* Changes after feedback

pkg/tsdb/cloudwatch/metric_data_input_builder.go

@@ -1,7 +1,6 @@
 package cloudwatch
 
 import (
-	"errors"
 	"fmt"
 
 	"github.com/aws/aws-sdk-go/aws"
@@ -30,11 +29,6 @@ func (e *CloudWatchExecutor) buildMetricDataInput(queryContext *tsdb.TsdbQuery,
 		ScanBy:    aws.String("TimestampAscending"),
 	}
 	for _, query := range queries {
-		// 1 minutes resolution metrics is stored for 15 days, 15 * 24 * 60 = 21600
-		if query.HighResolution && (((endTime.Unix() - startTime.Unix()) / int64(query.Period)) > 21600) {
-			return nil, &queryError{errors.New("too long query period"), query.RefId}
-		}
-
 		metricDataQuery, err := e.buildMetricDataQuery(query)
 		if err != nil {
 			return nil, &queryError{err, query.RefId}