IAM: Add teams/{id}/groups as a custom endpoint to Teams API (#114228)

* Add teams/{id}/groups as a custom endpoint

* TeamGroupsHandler OSS and Ent registration

* Update OpenAPI spec

* Add indexer tests for external group mapping

* Remove noopsearch

* Remove unnecessary interface declaration, fixes

* Chores

* fmt

* Rename constant

* Align the rest to the changes of main

* Update workspace

* Add missing file

pkg/registry/apis/iam/externalgroupmapping/models.go

@@ -0,0 +1,10 @@
+package externalgroupmapping
+
+import "k8s.io/apiserver/pkg/registry/rest"
+
+type TeamGroupsHandler interface {
+	rest.Storage
+	rest.Scoper
+	rest.StorageMetadata
+	rest.Connecter
+}

pkg/registry/apis/iam/externalgroupmapping/team_groups_noop.go

@@ -0,0 +1,58 @@
+package externalgroupmapping
+
+import (
+	"context"
+	"net/http"
+
+	iamv0alpha1 "github.com/grafana/grafana/apps/iam/pkg/apis/iam/v0alpha1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apiserver/pkg/registry/rest"
+)
+
+var _ TeamGroupsHandler = (*NoopTeamGroupsREST)(nil)
+
+type NoopTeamGroupsREST struct{}
+
+func ProvideNoopTeamGroupsREST() *NoopTeamGroupsREST {
+	return &NoopTeamGroupsREST{}
+}
+
+// Connect implements rest.Connecter.
+func (n *NoopTeamGroupsREST) Connect(ctx context.Context, id string, options runtime.Object, r rest.Responder) (http.Handler, error) {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		http.Error(w, "functionality not available", http.StatusForbidden)
+	}), nil
+}
+
+// New implements rest.Storage.
+func (s *NoopTeamGroupsREST) New() runtime.Object {
+	return iamv0alpha1.NewGetGroups()
+}
+
+// Destroy implements rest.Storage.
+func (s *NoopTeamGroupsREST) Destroy() {}
+
+// NamespaceScoped implements rest.Scoper.
+func (s *NoopTeamGroupsREST) NamespaceScoped() bool {
+	return true
+}
+
+// ProducesMIMETypes implements rest.StorageMetadata.
+func (s *NoopTeamGroupsREST) ProducesMIMETypes(verb string) []string {
+	return []string{"application/json"}
+}
+
+// ProducesObject implements rest.StorageMetadata.
+func (s *NoopTeamGroupsREST) ProducesObject(verb string) interface{} {
+	return s.New()
+}
+
+// NewConnectOptions implements rest.Connecter.
+func (s *NoopTeamGroupsREST) NewConnectOptions() (runtime.Object, bool, string) {
+	return nil, false, ""
+}
+
+// ConnectMethods implements rest.Connecter.
+func (s *NoopTeamGroupsREST) ConnectMethods() []string {
+	return []string{http.MethodGet}
+}