fix crate dragging with traders

[zjdtmkhzt]

About the PR

Apparently this has been broken for a while?
There is a pinned issue for it, to be honest, I never see those because I never look to the pinned issue area.
fixes #2061
@pali6 writes that it should be it's own proc, honestly, I don't see the need for that, it seems like a simple typecheck to me but what do I know.
Anyway, even if the way I fixed it is bad, it's probably better than leaving it broken for another 5 months.^^

Why's this needed?

It's a pretty cool feature!

Changelog

(u)zjdtmkhzt
(+)Dragging crates onto traders to sell their contents should now work again for all types of items.

[zjdtmkhzt]

Is the issue something like white weed vs normal weed?
In that case we could either just take care with the order in which commodities are stored, or we first check for exact matches and then just types.
Not sure if we already have a thing like that for regular trades? I didn't see one.

[zjdtmkhzt]

Yeah, lol, don't merge this yet, right now you get the money for all the types your item applies to.^^

[zjdtmkhzt]

ok, done, moved it to its own proc!