component AP gateway: use createActivity in mbdata2APitem

sat/plugins/plugin_comp_ap_gateway/__init__.py

@@ -802,6 +802,7 @@ class APGateway:
         actor_id: str,
         object_: Optional[Union[str, dict]] = None,
         target: Optional[Union[str, dict]] = None,
+        activity_id: Optional[str] = None,
         **kwargs,
     ) -> Dict[str, Any]:
         """Generate base data for an activity
@@ -818,7 +819,8 @@ class APGateway:
             raise exceptions.InternalError(
                 f'"target" is mandatory for activity {activity!r}'
             )
-        activity_id = f"{actor_id}#{activity.lower()}_{shortuuid.uuid()}"
+        if activity_id is None:
+            activity_id = f"{actor_id}#{activity.lower()}_{shortuuid.uuid()}"
         data: Dict[str, Any] = {
             "@context": "https://www.w3.org/ns/activitystreams",
             "actor": actor_id,
@@ -1615,15 +1617,9 @@ class APGateway:
                         mb_data
                     )
 
-        ap_item = {
-            "@context": "https://www.w3.org/ns/activitystreams",
-            "id": url_item,
-            "type": "Create",
-            "actor": url_actor,
-            "object": ap_object
-        }
-
-        return ap_item
+        return self.createActivity(
+            "Create", url_actor, ap_object, activity_id=url_item
+        )
 
     async def publishMessage(
         self,