Enable category toggle in pickup selectors

[IndecisionTree]

Summary

Interface "Enable category toggling in pickup selectors"

Purpose of change

This change allows toggling between category view and hierarchy view in pickup menus.

Describe the solution

toggle_categorize_contained() now categorizes or uncategorizes all column entries by either adding or removing their custom category. To preserve invlets between the map and selection columns, prepare_layout() is called directly and the ui is invalidated, but not marked for resize, so that a redraw will occur but invlets will not be reassigned (mark_resize() would end up calling prepare_layout() in the resize callback, which would call reassign_custom_invlets() and that would remove the selection columns invlets). All selected entries will then be re-toggled with their new invlets after paging.

Describe alternatives you've considered

Somehow getting selection column entries to link to the other columns and then special-casing the selection column in layout code to avoid invlets being clobbered. This felt like a more extensive change which would require rewriting many things.

Testing

Tested with an inventory full of items, some containers, and gear ensuring that categories toggled properly and columns were in sync. Also tested other selection menus (multidrop and inventory) to ensure nothing broke.

Additional context

Thanks to @andrei8l for the code to get this started!

Demo:

pickup_toggle.mp4