Memory leak in wave_picker::get_graph

[klem23]

We create a copy of the graph buffer, send the pointer to the client and nobody delete it

[klem23]

False it's deleted in CurveDraw::send_grap which is the client of the CurvePicker::get_graph (the new name of wave picker).

Perhaps we don't need this array memory copy in CurvePicker::get_graph, as this data should only be read by the caller.

I let the issue open to see what to decide with this memory protection/copy.