Send DeepL translation requests in multiple batches

[schorsch]

I did get an unspecified error when sending 2000+ translations to deepl. The author of the deepl gem has relased a new version where he added an specific error when hitting a limit.

This PR also handles deepl's target locale requirement for EN and PT which need their sub-version defined e.g. EN-US.
This can be a potential 'breaking' change for users still using EN as plain target, as i added an error for this case. See https://www.deepl.com/de/docs-api/translate-text/translate-text/ with their target_lang description

[glebm]

The API docs say that the the language without a region is supported for backwards compatibility. Perhaps we should issue a warning instead?

[schorsch]

yes that may be a bit nicer, i'll convert that to a warn_deprecated, as thats what i found in other regions of the gem.

[schorsch]

Btw. i get an error using a deepl pro key for the spanish test translations:

     Failure/Error: expect(task.t('common.hello', 'es')).to eq(text_test[2])
     
       expected: "Hola, %{user} ¡O'Neill! Como estas?"
            got: "¡Hola, %{user} O'Neill! ¿Cómo estás?"

are you running those test too maybe with the free api and it has a different output? Else i would fix those tests too.

[glebm]

Yeah these tests can be a bit flaky. Feel free to update

[glebm]

By the way, we're not currently handling placeholders correctly. This is tracked in #417

[schorsch]

Thanks for merging!

By the way, we're not currently handling placeholders correctly. This is tracked in #417

Thanks for the hint, i'll keep an ey on that, so far i had not had any exceptions my target app. Hard to tell how deepl maybe fixed any issues.