The backend previously passed an abstract is_admin_or_owner boolean
flag in the LiveKit token. That kept the frontend minimalistic and
saved it from having to handle role comparisons.
As we introduce more features that need to distinguish between the
room owner and admins, refactor the token to carry the role
directly. The frontend can then derive the relevant flags from a
richer piece of information.
Add an endpoint that allows updating a user's role while in a
meeting. The goal is to let users promote other connected
participants to admin or moderator, so the burden of administrating
a meeting can be shared.