[fix] Apply scroll to long strings in user message

[iseabock]

Motivation and Context

User noted that when extra long string are present in the user message, the entire UI get a x scroll. Where an x scroll for the message only would be desired.

Description

This PR adds an x-scroll: auto the user message

Contribution Checklist

• I have built and tested the code locally and in a deployed app
• For frontend changes, I have pulled the latest code from main, built the frontend, and committed all static files.
• This is a change for all users of this app. No code or asset is specific to my use case or my organization.
• I didn't break any existing functionality 😄