Mega Man buster aliasing

BUR #24996 has been approved by @nonamethanks.

create alias z_buster -> zero_buster

Somebody made two separate buster tags for Zero, likely on purpose because they seem to be for during X1 and after. However, that seems slightly unnecessary. While Zero's buster retains unique designs in both tags, ultimately it seems unnecessary to separate both.

BUR #24997 has been rejected.

create alias x_buster -> mega_buster

Possibly unnecessary. The differences are as follows-

Mega Man's buster is always the same model. Sometimes it gets drawn with a yellow column across it. Any time he uses a different power, it changes color to match his palette.

X's buster is usually the same model. This changes across the various armor types (See wiki) he collects in different games. In the end, it's still a mega buster, isn't it?...

The bulk update request #24996 (forum #275778) has been approved by @nonamethanks.

This bulk update request is pending automatic rejection in 5 days.

This bulk update request has been rejected because it was not approved within 45 days.

The bulk update request #24997 (forum #275779) has been rejected by @DanbooruBot.

BUR #26567 has been approved by @nonamethanks.

create alias zero_buster -> arm_cannon
create alias x_buster -> arm_cannon
create alias mega_buster -> arm_cannon

I'm not sure in retrospect when we need a unique tag for these, when they're always going to be attached to their respective character.

The bulk update request #26567 (forum #281953) has been approved by @nonamethanks.