Spin out components for:
* MessageBox: draw a chat message in the chat history panel as well as reused
in the Report Modal.
* WhoListRow: provides a consistent UX for the Who List and Watching tab. On
the Watching tab, the video button is replaced with the boot from video.
Other changes:
* Move VideoFlag into its own separate ES module.
* Emoji available reactions are moved into MessageBox.
* On WhoListRow: usernames are clickable to also open their profile page.
* On WhoListRow: the Watching tab is now sortable and follows the user's
sort selection like the Online tab does.
Noah