Widgets support is incredibly useful and so is this button, but it has a
few problems. The most obvious is that it's still enabled even if you
don't actually have the permission to start Jitsi meetings, so I fixed
that. I also made sure it's hidden when viewing spaces too.
Another problem is that you can't easily tell if a meeting is currently
in progress either, nor do we have a good icon for that in Breeze. So I
changed the tooltip and colored the icon in this case.
The final problem I fixed is something not exclusive to NeoChat, but
generally all chat applications with this feature - there's no
confirmation! To stop "butt-dialing" random people or rooms, I added a
prompt before starting or joining a meeting.
