More proximity fixes

Welder packs, compressed matter implants, null rods and robotrays.

Only three more places that the signature of `afterattack` looks like it needs a `proximity` var, I've left all three for various reasons:
* `code/game/objects/items/weapons/cards_ids.dm L108` (emag) because it seems to work as-is without `proximity`
* `code/game/objects/items/weapons/paint.dm L169` because it's commented out
* `code/WorkInProgress/SkyMarshal/portalathe.dm L8` because it's not marked for inclusion in the .dme