Crop long strings in GitLab Duo Chat

What does this MR do and why?

Crop long strings in GitLab Duo Chat

Changelog: fixed

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

Make sure Gitlab Duo is working on your local setup by following these steps

1. Open the Gitlab Duo chat in the group where you enabled the Ultimate license in the above setup process
2. Click on Help in the left navbar and then click on Ask Gitlab Duo
3. After the chat window is opened , try typing in longs strings or urls if testing snippets , see that it does not break the UI

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #417726