bug#47631: Add graphical installation and solve tons of headache

[bo0od]

Hi There,

According to my communications on IRC i see that guix doesnt want to 
have an offline installation, Which mean it need internet connection 
available at the installation process.

This is fine except when user having either static-ip or using VM which 
doesnt give readable network interface to the distro inside it (falling 
into same category of static-ip).

solving/giving:

- Adding static IP and so as manually installing is not well documented 
and need knowledge and skills (very faraway to be handled by new 
users)check #47630

- Easiness of modifying things e.g instead of using tens of commands it 
will be replaced with couple of clicks and for surely less typing 
(compare gparted vs parted steps or network-manager vs ip commands and 
so on). You can checkout many distros whos giving this opportunity like 
nixos, trisquel/triskel, mint...etc

- Give trial usage of the distro for the user before installing it

...etc

And any user who doesnt want GUI he can switch to tty for commands or 
textual installation. (The image of the guix will be bigger for surely, 
But as they say the bigger the better)

ThX!