chatview: long displayname in message bubble

Bug report form

Describe your environment

Please specify the following:

• Jami version: 202401241542 (ubuntu store)

Steps to reproduce

added good-first-issue bug UI/UX labels

Directly related to #1550 (closed)

https://review.jami.net/c/jami-client-qt/+/27554

closed

mentioned in commit 0b96cf5f