fix DarkSteel and other EIO items display

[ghostflyby]

DarkSteel tools and armors implement their isDamaged() method as returning a constant false, causing handleDefault to return null on such items when ShowWhenFull config set to true.

In order not to add a extra check for handleDefault, changes are made inside handleDarkSteelItems method.

Other possible, but in my opinion, problematic fixes are there.

1. This can also be fixed on the EIO side, but such a wired constant false might be intended for other uses which is far beyond my knowing.
2. A simple fix could be changing the handleDefault to check item damage by comparing max and current, but other mods might override the isDamaged method too to do something else.

As a result this PR might seem more complex then it might should have been.

[Caedis]

Huh, I didnt even think to check how EIO handled damaged items. Good catch