Draft: move Drawing GuiCommand to gui_drawing module

Also, finally the command is removed from the toolbar
as the Drawing Workbench is obsolete since v0.17.

The command is still loaded and defined by the workbench
but it is no longer presented to the user interface in the menu
or toolbar.

src/Mod/Draft/draftutils/init_tools.py

@@ -86,7 +86,7 @@ def get_draft_modification_commands():
             "Draft_WireToBSpline", "Draft_Draft2Sketch",
             "Draft_Slope", "Draft_FlipDimension",
             "Separator",
-            "Draft_Shape2DView", "Draft_Drawing"]
+            "Draft_Shape2DView"]
     return lst