[Feature]: Sort bags to stack any stackables

[psykzz]

Describe the feature

When clicking sort bags, attempt to first stack any stackable items.

Describe the implementation

During "sort" first loop through and find items that are not max stack.
Stack items
Continue with sort.

Expectation

I would expect clicking sort bags to have stacked all this wool cloth.

[Cidan]

In Classic this is because Blizzard removed the API from Classic to sort bags entirely, to make sure Classic was authentic, bag management headaches and all.