message: Show full thread message in hover title on thread summary
diff: @@ -104,7 +104,7 @@ export const ThreadMessagePreview = ({ thread, showDisplayname = false }: IPrevi
  { showDisplayname && <div className="mx_ThreadSummary_sender">
  { lastReply.sender?.name ?? lastReply.getSender() }
  </div> }
  - <div className="mx_ThreadSummary_content">
  + <div className="mx_ThreadSummary_content" title={preview}>
  <span className="mx_ThreadSummary_message-preview">
  { preview }
  </span>
  