Merge if item stackable exist into inventory from other inventories

Imported from legacy Flarum.
Original author: Raziel (Flarum #1147)

The idea that i have is to reunite all items from various inventories into one. With an option, I want to select storage 1 to reunite all stackable items content into storage 1 from other storages.
For example: I have elunium in storage 1,2,3 for various reasons.

Selecting that option, I set storage 1 as main and 2-3 as delegate. The items in 1,2, and 3 merge into storage 1, and items only in 2-3 remain.

Imported from legacy Flarum.
Original author: Choi (Flarum #323)

Seems like it would be a lot of work for muh
so +1

but this would be super useful to keep storages organized