Add a signal for grouping objects to datacontrol plugin
currently rpcCallFunctionValue is used to group objects in datacontrol plugin. Since addEmptyObject is connected as a Queued connection, we can not be sure, that new objects were already processed by the addedEmptyObject slot of datacontrol plugin.
Addding a public signal to the datacontrol plugin which uses a queued connection to call groupObjects would simplify grouping from other plugins by just emitting this signal.
To upload designs, you'll need to enable LFS. More information