Introduce run_listbox_with_data()

[mooffie]

The problem:

Functions that use run_listbox() can be complicated and breakable, if they need to figure out some pointer given the number of the item selected.

(For example, in the case of ​edit_window_list() this will make its code break if we change how widgets are Z-ordered --which was the 1st solution I tried for #3760.)

The solution:

A listbox can already store pointers. So we introduce a variant of run_listbox() with returns pointers. We then use it to simplify a couple of functions.