* feat(recording): add sounds for when recording starts and stops

* squash: use constants, play sounds for file only

* squash: rename recordingStopped.mp3 -> recordingOff.mp3

* squash: flip var declaration for alpha order

Cleaning up call flow presence stanzas and cancel triggers.

Fixes: https://github.com/jitsi/jitsi-meet/issues/3086

This happend after initialization and joining a conference for the first time
in JitsiMeetView.

Layout:

Use an absolute-fill view as the background with the sidebar on top of. This
greatly simplifies styling, as there is no need to calculate how large the
backdrop needs to be.

Animation:

Switch to a translateX transform animation. This serves 2 purposes: first,
there seems to be a bug somewhere in React Native 0.51-0.55 where the content
that is being animated starts to be clipped. Very weird! But more importantly,
translateX transmorm animations are supported by the native animation driver!

https://facebook.github.io/react-native/blog/2017/02/14/using-native-driver-for-animated.html
8f5ebe5952/Libraries/Animated/src/NativeAnimatedHelper.js (L138-L176)

This makes the animation more performant and buttery smooth.

Some small cleanups are also included here.

Fragment now works on both React and React Native, so use it.

Also bump React to 16.3.2, since it's required.

It's removed in RN >= 0.55. This aligns the project with the official
documentation: https://facebook.github.io/react-native/docs/integration-with-existing-apps.html#configuring-cocoapods-dependencies

Properly propagating call id for call response handling.

Previously a new call id was generated for INVITE and CANCEL.
Now the id generated during the initial INVITE will be used for
corresponding CANCEL events. Also, adding the ability to
trigger a call cancel via the poltergeist update api.

Instead of keeping dominant speaker locally, get it from redux and be
updated when the dominant speaker changes. This is in an attempt to mimic
the video layout being reactified and connected to redux.

The goal will be to make video layout stateless and instead
get all state from redux.

No longer triggering calls for the Invited status of a poltergeist.

The current poltergeist http api immediately returns
and does not wait for async work in the handler to finish. This
mostly occurs when a public asap key needs to be fetched due
to a cache miss. The fix implements the strategy described at
https://prosody.im/doc/developers/http.html

If CONFERENCE_LEFT would arrive with a delay while we're in
another conference already, then the wake lock could end up in
an incorrect state.

Use state listener to simplify the logic and not care about the actions
since the fullscreen flag is calculated from the current conference
state.

Try to use the getCurrentConference function wherever the indention is
to check for the current conference.

The visibility of the toolbar can be toggled by interacting with the main screen.
This change allows the toolbar to be configured to be 'always visible'. This voids
the 'toggle' functionality.

This includes recording agents, for example.

Simplify parts of the logic introduced in
11b7144ad0.

Specificaly, using all the state change avoiding functions doesn't give us much
since we need to copy the state for sure.