Communication: Allow to search reply content

[xHadie]

Is your feature request related to a problem?

Fruitful content of discussions would probably be nested more deeply in replies to a message.
Students/tutors/instructors might attempt to search for that specific information and be surprised that the search functionality is unable to elicit a search result.

Describe the solution you'd like

Allow to enable searching for reply content:

• Show the message (thread) as a result if one of its replies matches the search query
• Show only the replies that match the query (preferably indented to the main message) in the search result view

Describe alternatives you've considered

No response

Additional context

Reply not shown in the result

[cremertim]

@PaRangger can you take a look at this PR. I think this issue is already solved