Imply firearm foregrip types

BUR #58557 is pending approval.

create implication angled_foregrip -> foregrip
create implication vertical_foregrip -> foregrip

Do you think we really need this? If we don't I think it's acceptable to request nuking foregrip instead, since it can be substituted with *_foregrip.

Voting meh on it because I'm fine either way: nuking foregrip into it's split versions, or aliasing both the split versions to foregrip instead.

Definitely don't believe that all three tags are worth keeping. It's just more firearms parts tag padding.

BUR #58573 is pending approval.

deprecate foregrip

Alternate option, still makes sense.

BUR #58610 is pending approval.

create alias angled_foregrip -> foregrip
create alias vertical_foregrip -> foregrip

Alternative to BUR #58573 above, going the other way, just for voting purposes.