Domain IDs are at least 16 bits for most hypervisors, theoretically
event 32-bits.  3 characters is clearly too small an alignment.
Increase alignment to 5 characters to allow 16-bit domain IDs to
display cleanly. Commonly seen with LXC where domain IDs are the
process IDs by default.  Also increase the 'name' field from 20
to 30 characters to cope with longer guest names which are quite
common