fix: Avoid reports of legitimate content

Social media platforms use `Melden` to report inappropriate content.
In the teaching context it is common in German to report yourself if
you have a question (sich melden). It appears that students report
content to get attention from the teacher because no reported content
includes inappropriate content.

It is the hope that `Inhalt melden` makes it clearer that this a
content moderation function.

The popup message also asks the student if he wants to report the
content. This should make it clearer that is not "sich melden". Due
to the Trubo.js migration this message is not always displayed, or
the students ignore the message. #3021 might also contribute to the
issue.

Author: arkirchner

config/locales/de/request_for_comment.yml

@@ -44,7 +44,7 @@ de:
     passed: Erfolgreich
     report:
       confirm: Möchten Sie diesen Inhalt melden?
-      report: Melden
+      report: Inhalt melden
       reported: Vielen Dank, dass Sie uns auf dieses Problem aufmerksam gemacht haben. Wir werden uns in Kürze darum kümmern.
     runtime_output: Programmausgabe
     send_thank_you_note: Senden