Allow selecting the source language for all record types not just tt_content
It's already possible to select a source language for a new tt_content localization.
Having a setup like EN (default 0), DE (1), ES (2) one can translate content in ES and select DE as source language. This does however not work for other/custom record types, at least not in the Backend (Recordlist GUI).
Imported from T3cm 2020 (https://notes.typo3.org/s/WpKeyLuYr)
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