Typo and better wording for german validator translation
minor #9599 [Validator] Typo and better wording for german validator translation (Danez)

This PR was submitted for the master branch but it was merged into the 2.3 branch instead (closes #9599).

Discussion
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[Validator] Typo and better wording for german validator translation

Follow up of #9588 as supposed by @craue

Commits
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263b618 Typo and better wording for german validator translation
Remove usage of deprecated _scheme in Routing Component

Instead correctly use the array of schemes from the Route.
Also adjusted the dumpers to dump the correct data.

I extended the tests to not only test the deprecated behavior, but also
the new schemes-requirement.