feat: option to disallow public org registration (#6917)

* feat: return 404 or 409 if org reg disallowed

* fix: system limit permissions

* feat: add iam limits api

* feat: disallow public org registrations on default instance

* add integration test

* test: integration

* fix test

* docs: describe public org registrations

* avoid updating docs deps

* fix system limits integration test

* silence integration tests

* fix linting

* ignore strange linter complaints

* review

* improve reset properties naming

* redefine the api

* use restrictions aggregate

* test query

* simplify and test projection

* test commands

* fix unit tests

* move integration test

* support restrictions on default instance

* also test GetRestrictions

* self review

* lint

* abstract away resource owner

* fix tests

* lint

internal/repository/restrictions/aggregate.go

@@ -0,0 +1,26 @@
+package restrictions
+
+import (
+	"github.com/zitadel/zitadel/internal/eventstore"
+)
+
+const (
+	AggregateType    = "restrictions"
+	AggregateVersion = "v1"
+)
+
+type Aggregate struct {
+	eventstore.Aggregate
+}
+
+func NewAggregate(id, instanceId, resourceOwner string) *Aggregate {
+	return &Aggregate{
+		Aggregate: eventstore.Aggregate{
+			Type:          AggregateType,
+			Version:       AggregateVersion,
+			ID:            id,
+			InstanceID:    instanceId,
+			ResourceOwner: resourceOwner,
+		},
+	}
+}