feat(backend): add SCIM for user provisioning (#12713)

* Add SCIM
Closes https://github.com/inventree/InvenTree/issues/6339

* also test scim

* extend testing with conformance suite

* fix test suite results

* coverage completion

* fil test gaps

* add missing schema values

* fix more type issues

* fix error view

* remove route from OpenAPI

* add changelog entry

* add codeowners

.github/CODEOWNERS

@@ -8,6 +8,8 @@
 # Installer functions
 .pkgr.yml               @matmair
 Procfile                @matmair
-runtime.txt             @matmair
 /contrib/installer      @matmair
 /contrib/packager.io    @matmair
+
+# Auth federation
+/src/backend/scim/                @matmair