Alerting: declare authorization actions, scopes and roles for fine-grained access (#45748)

* add actions, roles and route mapping for rule permission
* add instance\notification actions
* do not declare alerting roles if no feature flag is set (temporary)

pkg/services/ngalert/api/api.go

@@ -8,6 +8,7 @@ import (
 	"github.com/grafana/grafana/pkg/api/routing"
 	"github.com/grafana/grafana/pkg/expr"
 	"github.com/grafana/grafana/pkg/infra/log"
+	"github.com/grafana/grafana/pkg/services/accesscontrol"
 	"github.com/grafana/grafana/pkg/services/datasourceproxy"
 	"github.com/grafana/grafana/pkg/services/datasources"
 	apimodels "github.com/grafana/grafana/pkg/services/ngalert/api/tooling/definitions"
@@ -70,6 +71,7 @@ type API struct {
 	MultiOrgAlertmanager *notifier.MultiOrgAlertmanager
 	StateManager         *state.Manager
 	SecretsService       secrets.Service
+	AccessControl        accesscontrol.AccessControl
 }
 
 // RegisterAPIEndpoints registers API handlers