[WIP] [DE-DE] Add German language support

[sl1txdvd]

This is a work in progress and not meant to be merged. I have to work on Java files next.

[nils-se]

Hey, I would love to have german support for numbers in dicio. It would enable all the other skills. Is there anything I can help with? And thank you :)

[KR4U7H3R]

Same here. Any news/help needed?

[KR4U7H3R]

Is there any progress, or should we try to continue the work by ourselves?

[acidcoke]

It's been two years. I think it's safe to say this is not being worked on anymore.

[numerfolt]

Can someone approve "date_time" and all the .word files?
They are looking good to me.

I am looking into the other files too, but those are definitely okay

[Stypox]

Thanks @sl1txdvd for your contribution! I am very sorry for coming back to it only now :-/. I have put very little attention on this repo until now, since I made changes to the interface a few times and I had plans to change it again to make it even more flexible (basically using the code in Dicio's skill input matching implementation), but in the end I likely won't do anything like that as it would be too complicated and give few benefits.

I converted the code to Kotlin, rebased on master, and fixed some compilation issues. However, this PR does not implement the parser, which is the hardest part. Tests are also failing, here is a report from Android Studio:
Test Results - Tests_in_'org_dicio_numbers_lang_de'.html

@sl1txdvd let me know if you still intend to work on this and implement the parser part. Otherwise I'll close this PR and advise other contributors to open a new PR (and point them here to copy over what was already implemented, like @numerfolt suggested).

Btw, I now know a tiny bit of German so I might be able to help out a bit more ;-)