Add automatic testing for live environment and installation

[ventureoo]

This adds automatic testing of ISO environment and system installation process through calamares using the quicktest project. The main motivation for this is to make maintaince easier, speed up the process of releasing new ISOs and improve quality of testing as it allows to test many configurations at once for each change.

It works pretty simple: Testing takes place in QEMU virtual machine, with which quicktest communicate via socket, through which predescribed actions are transmitted - keystroke sequences, which are described as simple shell script in the testcases directory. Control of the process is carried out by sequential capture of screenshots and it analysis using OCR (tesseract). The main limitation here is that you can’t pass input with a "virtual" mouse, but usually keyboard control is enough to check many things like installation process.

At the end, result of installation timelapse is uploaded into the artifacts along with ISO.

Of course, this does not allow us to identify in advance all hardware-specific issues (at least now, if we had our own runners, we could test and it just by passthrough GPU and other things in VM), but at least it gives a good QA on changes in calamares.

Some future work:

• Add tests for BIOS installation (right now it's UEFI only)
• Add tests for full disk encryption
• Add installation tests via New-Cli-Installer
• Integrate tests with calamares tree? Can be useful when developing and bisecting problematic changes before merging.