Puma clean-up

BUR #35780 has been rejected.

rename cougar_(animal) -> cougar
create alias cougar -> puma
create alias mountain_lion -> puma

For some reason we had two separate tags for cougars and pumas, despite those being the same thing, and cougar had an unnecessary qualifier because up until recently an artist tag used 'cougar' as its name. With the animal tag being given a fairly redundant wiki just now, let's sort this out before it gets any more messy.

I personally prefer cougar as the primary name, but as long as they're grouped I have no serious objections.

BUR #36081 has been approved by @evazion.

rename cougar_(animal) -> cougar
create alias puma -> cougar
create alias mountain_lion -> cougar

I'll use cougar as the primary name, since that's what Wikipedia uses.

The bulk update request #36081 (forum #332852) has been approved by @evazion.

The bulk update request #35780 (forum #331498) has been rejected by @evazion.