The files styles.js are used (pretty much) on React Native only and each
of them exports 1 name. Export it as default to cut down on source code.

When entering audio-only mode, VideoBridge is instructed to stop sending
remote videos. However, if the instruction fails because DataChannels do
not work, for example, then the app continues to display the remote
videos. Even though they're received in the case of such a failure, no
videos are to be displayed in audio-only mode.

Introduce certain React Components which may be used to write
cross-platform source code such as Audio like Web's audio, Container
like Web's div, Text like Web's p, etc.

Also move (native) avatar style to film-strip styles, since  that's where it
applies. This is analogous to how the large-view avatar is styled.

This reverts commit 739298c782.

They better represent if a participant has video available or not. There are
cases when even a participant in the last N set would not have video because it
disconnected momentarily, for example.