Add missing firmware-row.ui to POTFILES.in

Add spacing between the "plus" icon and the "dropdown arrow" icon, so
the button looks less busy.

While the experience is significantly better for the majority of users
when they are able to match an operating system (or similar), it is
understanble that the relationship between OSes might be unclear to
some users.

This way, the UI should continue encouraging the user to select an
OS, but it shouldn't block the VM creation for when an OS isn't
selected.

Fixes #922

The new implementation of the VM creation widget wasn't accounting
for the custom storage limits. It was always creating the storage
with a limit equal to the recommended storagel limit from libosinfo.

Including the new slirp dependency that provides the "user" network
for VMs.

Don't check for CHANGES_DONE_HINT before saving the user-edited domain
configuration. Checking this would temporarily change the path of the
file that was being edited (appending an "~" to the path), which ended
up leading to a "No such file or directory" error everytime the user
saved their custom domain configuration.

The downside to this change is that the domain configuration is now
saved everytime the user writes to the .txt file, instead of waiting for
the likely last change in a set of changes.

This represents the configuration that will be used on the next boot of
the domain. This is important for when Boxes updates the VM resources
such as RAM/Storage-limit, which would require a new OS boot anyway.

By using a LibvirtMachine.title property which sets both the libvirt
domain xml title and the Boxes config-file property that stores the
VM names.

p.s.: The existance of both, as of now, is for the SearchProvider to
be capable of listing VM names without having to involve libvirt.

Signed-off-by: Felipe Borges <felipeborges@gnome.org>

Update to upstream version '44~rc'
with Debian dir 74b033e048830d5387cb309ba2ebb76d212b4392

WIP

Fixes #936

Fixes #937

Update to upstream version '44.0'
with Debian dir e3b9905ec0dc273e04be2c23e14dc3478d7be9cb