feat: add api-based extension & external data tool & moderation backend (#1403)

Co-authored-by: takatost <takatost@gmail.com>

api/services/code_based_extension_service.py

@@ -0,0 +1,13 @@
+from extensions.ext_code_based_extension import code_based_extension
+
+
+class CodeBasedExtensionService:
+
+    @staticmethod
+    def get_code_based_extension(module: str) -> list[dict]:
+        module_extensions = code_based_extension.module_extensions(module)
+        return [{
+            'name': module_extension.name,
+            'label': module_extension.label,
+            'form_schema': module_extension.form_schema
+        } for module_extension in module_extensions if not module_extension.builtin]