This diff updates the `ThreadMember` component so that it matches the new UI redesign. This diff also resolves an issue where long usernames were not properly truncating
For context here is what the thread member component looks like on figma:
{F1107280}
Linear task: https://linear.app/comm/issue/ENG-4161/additional-empty-spaces-between-users-on-members-list
Depends on D10922