feat: return removed item when removing from weighted container

[LordMidas]

Seems like a pretty straightforward feature to have and is consistent with array.remove and delete for table slots.

Allows to do the following to roll items from a container while removing them so they cannot be rolled more than once:

local item1 = weightedContainer.remove(weightedContainer.roll());
local item2 = weightedContainer.remove(weightedContainer.roll());

instead of

local item1 = weightedContainer.roll();
weightedContainer.remove(item1);
local item2 = weightedContainer.roll();