update the localdev grid's secrets and other configuration to reflect this

testing and production are broken by this commit since they have not been
updated similarly

It is no longer required to add IP addresses to the Vagrant-generated ssh
configuration because the Vagrant-configured hostnames now match up with the
names morph will try to use to connect to the VMs.

Just require hostName and domain instead of an extra publicIPv4 option.  Leave
behind a similar option, `publicAddress`, just in case it needs to be
overridden at some point, but stop supplying a value for it anywhere.

Put its contents in it and then use them from there instead of importing them
all over the rest of the code.

Also change the `domain` parameter for Grafana to always
use that beautiful name - besides display it's cosmetic anyway
IIANM so I'll not parametrize it for now.

For consistency reasons: Even if they had a perfectly good swap
partition already, and also for AWS hosts.

See https://whetstone.privatestorage.io/privatestorage/PrivateStorageio/-/merge_requests/103#note_13854

Remove the VirtualBox GUI, see
https://search.nixos.org/options?channel=21.05&show=virtualisation.virtualbox.host.headless&from=0&size=50&sort=relevance&query=virtualbox