UKI: (kairos-agent) install

[mudler]

Follow-up of #1151 #872

Currently, doing a UKI installation is a manual thing. There is a subcommand to do a UKI installation. We can to make this automated. kairos-agent should detect that is has booted a UKI image and should do a UKI installation if that's the case.

Acceptance Criteria

• All installation types (automated, manual, interactive) should all perform a UKI installation when system is booted with UKI Run install off the same command kairos-agent#196 and Fix uki mode detection kairos-agent#198
• Remove the hardcoded kairos user that we added for UKI uki fixes for cc files packages#608
• Check that datasource also works with the above installation types.

[Itxaka]

• interactive install works perfectly
• datasources work as expected
• manual-install passing a cc doesnt seem to work as expected, final config doesnt appear to be there, investigating

[Itxaka]

manual install DOES work actually, I just screwed the tests :)

[Itxaka]

This is all done!