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/utils_test.go

@@ -17,6 +17,7 @@ import (
 	"github.com/grafana/grafana-aws-sdk/pkg/awsds"
 	"github.com/grafana/grafana-plugin-sdk-go/backend"
 	"github.com/grafana/grafana/pkg/setting"
+	"github.com/stretchr/testify/mock"
 )
 
 type fakeCWLogsClient struct {
@@ -190,6 +191,15 @@ func newTestConfig() *setting.Cfg {
 	return &setting.Cfg{AWSAllowedAuthProviders: []string{"default"}, AWSAssumeRoleEnabled: true, AWSListMetricsPageLimit: 1000}
 }
 
+type mockSessionCache struct {
+	mock.Mock
+}
+
+func (c *mockSessionCache) GetSession(config awsds.SessionConfig) (*session.Session, error) {
+	args := c.Called(config)
+	return args.Get(0).(*session.Session), args.Error(1)
+}
+
 type fakeSessionCache struct {
 	getSession    func(c awsds.SessionConfig) (*session.Session, error)
 	calledRegions []string