PLEASE NOTE THAT THIS DIFF AND SUBSEQUENT DIFFS IN THIS STACK WILL NOT BE LANDED UNTIL MORE OF THE REDESIGN IS READY SINCE THIS WILL CAUSE REGRESSIONS IN PROD
This diff updates the chat thread composer ui to match the ui in the new web app redesign. In this diff I did the following:
- Added a bottom border inset to the search container when a user is selected
- Added a border radius to the hover effect
Linear task: https://linear.app/comm/issue/ENG-5936/message-list-ui-redesign
Depends on D10549