Add missing ukrainian translation

[t0rik]

ukrainian translation

[Luzifer]

Thanks for updating the translations! There are still a few missing:

INFO[0000] validating language...                        lang=uk
WARN[0000] missing translation                           lang=uk translation_key=alert-insecure-environment
WARN[0000] missing translation                           lang=uk translation_key=btn-theme-switcher-auto
WARN[0000] missing translation                           lang=uk translation_key=text-invalid-files-selected
WARN[0000] missing translation                           lang=uk translation_key=text-secret-burned

[Luzifer]

One discussion with the machine-translator later: Would this make sense as Знищити? It at least seems to be (my knowledge of Kyrillic script is terrible) similar to the знищено you've used in the other translation PR…

If I got it correct, "знищено" means "destroy" and "Знищити" is similar while "Запали" is the literal "ignite" which I used for "burn secret", right?