Alerting: Migrate notifications API to app-platform SDK application (#104424)

* introduce alerting notification app
* move code as is and remove from old registry
* update api server registration
* update make file and remove unnecessary args, copy some useful make commands from dashboards
* update codeowners

* move constants inside module and remove dependency from grafana
* add support for selectors to the app builder

pkg/registry/apps/alerting/notifications/routingtree/authorize.go

@@ -0,0 +1,51 @@
+package routingtree
+
+import (
+	"context"
+
+	"k8s.io/apiserver/pkg/authorization/authorizer"
+
+	"github.com/grafana/grafana/pkg/apimachinery/identity"
+	"github.com/grafana/grafana/pkg/services/accesscontrol"
+)
+
+func Authorize(ctx context.Context, ac accesscontrol.AccessControl, attr authorizer.Attributes) (authorized authorizer.Decision, reason string, err error) {
+	if attr.GetResource() != ResourceInfo.GroupResource().Resource {
+		return authorizer.DecisionNoOpinion, "", nil
+	}
+	user, err := identity.GetRequester(ctx)
+	if err != nil {
+		return authorizer.DecisionDeny, "valid user is required", err
+	}
+
+	var action accesscontrol.Evaluator
+	switch attr.GetVerb() {
+	case "patch":
+		fallthrough
+	case "create":
+		fallthrough
+	case "update":
+		fallthrough
+	case "deletecollection":
+		fallthrough
+	case "delete":
+		action = accesscontrol.EvalAny(
+			accesscontrol.EvalPermission(accesscontrol.ActionAlertingNotificationsWrite),
+			accesscontrol.EvalPermission(accesscontrol.ActionAlertingRoutesWrite),
+		)
+	}
+
+	eval := accesscontrol.EvalAny(
+		accesscontrol.EvalPermission(accesscontrol.ActionAlertingNotificationsRead),
+		accesscontrol.EvalPermission(accesscontrol.ActionAlertingRoutesRead),
+	)
+	if action != nil {
+		eval = accesscontrol.EvalAll(eval, action)
+	}
+
+	ok, err := ac.Evaluate(ctx, user, eval)
+	if ok {
+		return authorizer.DecisionAllow, "", nil
+	}
+	return authorizer.DecisionDeny, "", err
+}