Glade files: Replace GtkTable with GtkGrid

* ui/developer/*.glade:
* ui/operator/*.glade: Change all GtkTable types to GtkGrid.
  Child items that should expand then have an hexpand=True in the
  <child> part instead of x_options=GTK_FILL in the <packing> part.
  The packing should also contain (and only contain) left_attach,
  width, top_attach, and height.