create desktop base image

[taukakao]

Feature Description

Currently, creating an image that switches out the desktop environment is very hard, since you have to recreate and track most of the desktop image.

Having a base image would make this process a lot simpler. That would mean that desktop image would only have Gnome specific things installed.

I would suggest creating both images in this repo tho to avoid having yet another repo which get increasingly difficult to manage.

[nisel11]

you should check a Kanola base image, it's maybe can be used for desktop base

[taukakao]

We just have to separate the Gnome parts from everything else, but yeah, this is basically what their base image does.

[mirkobrombin]

Definitely something we need.