Add db compact ability to ziti-controller command

[andrewpmartinez]

bbolt supports a compact command that can be used to reduce the size of databases. This can also be done via the Edge API w/ a database snapshot, but this is a very easy way for a sysadmin to do the same thing.

[andrewpmartinez]

The compact logic isn't exposed. Seeing if we can bolt to expose it here: https://github.com/etcd-io/bbolt/issues/247 . I put a PR up for them as well.

If not we can always copy it...