Feature: optional box naming/renaming as parameter

[bjne]

Often, remote boxes are named vagrant.box. I would love an optional parameter "name"
to allow direct naming of mutated boxes, since renaming is a hazzle.

example:

vagrant mutate https://atlas.hashicorp.com/CumulusCommunity/boxes/cumulus-vx/versions/3.0.1/providers/virtualbox.box libvirt cumulus-vx

[quanah]

This is along the lines of #78 and is pretty much mandatory now with the new box structure. :/