CloudMonitoring: Initial GCM Schema (#67739)

* Initial GCM schema work

- Split types for convenience
- Update conditionals where needed
- Update type references

* Add additional supporting types

* Add some more accessory and legacy types

* Add missing type

* Rename backend folder

* Add missing generated file

* Review

pkg/plugins/backendplugin/coreplugin/registry.go

@@ -10,7 +10,7 @@ import (
 	"github.com/grafana/grafana/pkg/plugins/backendplugin"
 	"github.com/grafana/grafana/pkg/plugins/log"
 	"github.com/grafana/grafana/pkg/tsdb/azuremonitor"
-	"github.com/grafana/grafana/pkg/tsdb/cloudmonitoring"
+	cloudmonitoring "github.com/grafana/grafana/pkg/tsdb/cloud-monitoring"
 	"github.com/grafana/grafana/pkg/tsdb/cloudwatch"
 	"github.com/grafana/grafana/pkg/tsdb/elasticsearch"
 	"github.com/grafana/grafana/pkg/tsdb/grafanads"