Adding a user with a long name as a request participant displays its name incorrectly

Issue Summary

When adding a user as a request participant, if that user has a long display name, its name won't be shown in the Request Participant field correctly, and we need to hover over it to see who is the user.

This was originally pointed out in a Community question, here: https://community.atlassian.com/t5/Jira-Service-Desk-questions/JSD-Request-Participants-field-Cannot-see-people/qaq-p/1448329

Steps to Reproduce

1. Create a user with a long display name
2. Add the user as a request participant to a JSD issue

Expected Results

User added to the request as a participant, with at least part of its name readable.

Actual Results

The whole user display name is replaced with ellipses, as shown in the screenshot below.

Workaround

Currently, there is no known workaround for this behaviour. A workaround will be added here when available