i18n: complete missing German translations + remove duplicate English key

[jonasschulze-dev]

Changes

• Added 77 missing entries to _locales/de/messages.json
• Removed a duplicated key from _locales/en/messages.json

Compared against the English source file.
Tried to keep the existing German translation style consistent.

[ImprovedTube2]

hi and thank you! @jonasschulze-dev

Did you come across difficult / impossible decisions? Which ones might still make sense discussing?
( images.google.com and or trends.google.com often might help.
I say all this by default to document and appreciate translators' efforts while fresh and remembered.)

@Termuellinator @css-smueller

[ImprovedTube2]

1971426 @jonasschulze-dev

[jonasschulze-dev]

Hi @ImprovedTube2!

I’ve now rebased on the latest master and updated the German strings to match the new English wording from #1971426.

Regarding difficult decisions: most strings were straightforward. I tried to stay consistent with the existing German style. Nothing major stood out that I felt needed discussion, but I’m happy to adjust anything if you or the other translators notice something.

Thanks!

[css-smueller]

old one fits better.

[css-smueller]

old one fits better, new one is too long

[jonasschulze-dev]

Thanks for the review, I’ve reverted the two German locale entries to the previous wording.