Add focal native docker image
I split this out of !68 (closed), so that we can merge the native focal image already. This helps to start clickable#277 (closed).
With this image I was able to compile and run our CMake app in desktop mode. I only had to change Ubuntu
by Lomiri
in the QML imports (a compatibility module is planned, so this could be omitted in the future).
The CI has a new job to build the image with tag 20.04
.
Edited by Jonatan Hatakeyama Zeidler