Add a command to restore from backup

[goldenapples]

Currently restoring an environment from a backup is a three-step process:

• download the backup to local with altis-cli backups
• scp this file to the sandbox with altis-cli stack scp
• expand the archive and run wp db import on the server

Since this is an action that may need to be taken in urgent situations, it would be nice to have the process simplified. I don't have clear details, but a restore command that handled all these steps would be great.

[rmccue]

Just to note, if you're in an urgent situation, please contact support who can restore from our actual backups instead of from the exports. This is both much faster for restoration and has less potential for data loss, as they back up the filesystem for the database directly.