Fixes welding hard hats having an invisible visor and updates said visor sprites

[AMyriad]

Document the changes in your pull request

So I noticed that welding hard hats didn't have any /mob/ sprite overlaying when toggled ON and the /obj/ sprite was overlaying...this which is the overlay for our old hard hat sprites if you couldn't tell

Definitely an oversight, so I grabbed the updated visor from upstream and...wasn't too happy with them So I tweaked those sprites a bit to look better, and then voila

Testing

Spriting

Tweaked to be a bit thicker than the original:

Wiki Documentation

I'll get around to it

Changelog

:cl: AMyriad, PositiveEntropy, The Shiptest Team bugfix: Welding hard hat visors are no longer invisible, and overlay correctly now imageadd: Added proper visor sprites for welding hard hats /:cl: