* feat(presence): display status in thumbnail and large video

- Create a React Component for displaying presence. It currently
  connects to the store for participant updates but in the future
  should not be as smart once more reactification occurs.
- Modify filmstrip css so the presence status displays horizontal
  center and below the avatar.
- Modify videolayout css so the presence status displays horizontal
  centered and with a rounded background.
- Dispatch presence updates so the participant state can be update.
- Update message position on large video update to ensure message
  positioning is correct.

* squash: do not show presence message if connection message is displayed

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.

We've had Filmstrip & LargeVideo React Components on mobile/React Native
from the start. We didn't have them on Web (because the rewrite in React
is not complete yet). However, that led to differences in the React
Component Conference on Web and mobile. In an effort to get closer to
merging the React Component Conference on Web and mobile, introduce the
React Components Filmstrip & LargeVideo on Web even if a minimal
render-only form at this time.

Until we make a decision on access modifier hints and adopt a respective
coding style, consistency is king.