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/storage/unified/search/builders/testdata/doc/external_group_mapping-mapping-with-team-and-group-out.json

@@ -0,0 +1,17 @@
+{
+  "key": {
+    "namespace": "default",
+    "group": "iam.grafana.app",
+    "resource": "externalgroupmappings",
+    "name": "mapping-with-team-and-group"
+  },
+  "name": "mapping-with-team-and-group",
+  "rv": 1234,
+  "fields": {
+    "team": "team1",
+    "external_group": "group1"
+  },
+  "title": "mapping-with-team-and-group",
+  "title_ngram": "mapping-with-team-and-group",
+  "title_phrase": "mapping-with-team-and-group"
+}

pkg/storage/unified/search/builders/testdata/doc/external_group_mapping-mapping-with-team-and-group.json

@@ -0,0 +1,14 @@
+{
+  "apiVersion": "iam.grafana.app/v0alpha1",
+  "kind": "ExternalGroupMapping",
+  "metadata": {
+    "name": "mapping-with-team-and-group",
+    "namespace": "default"
+  },
+  "spec": {
+    "teamRef": {
+      "name": "team1"
+    },
+    "externalGroupId": "group1"
+  }
+}