commandline: Add option to run a VM by name

Add a new option to start an already created VM using the command line
`gnome-boxes open-vm-by-name vm_name`. If the user types an invalid vm
name gnome-boxes will return all the valid options.

Issue #33
4 jobs for vm_commandline in 55 minutes and 13 seconds (queued for 5 seconds)
latest
Status Job ID Name Coverage
  Test
passed #114156
flatpak

00:50:17

 
  Review
passed #114157
review

00:00:46

manual #114158
allowed to fail manual
stop_review
 
  Cross Distro
passed #114159
fedora:rawhide

00:04:09