React (pun intended) to prop changes, that is, load the new specified URL.

In addition, fix a hidden bug in loading the initial URL from the linking
module: we prefer a prop to the URL the app was launched with, in case somehow
both are specified. We (the Jitsi Meet app) are not going to run into this
corner case, but let's be defensive just in case.

* fix(filmstrip-only): vertically align center the toolbar

Use top 50% to position the toolbar's top at the vertical center
of the iframe. Then use transform 50% to move the toolbar itself
up 50% so its middle matches the middle of the iframe.

* squash: toolbox should center with filmstrip

Apparently iOS doesn't like dangling background tasks very much, so update the
background timers plugin with a version which fixes this.

https://github.com/ocetnik/react-native-background-timer/pull/38

Also accomodate for the API changes upstream.

Credits to @lyubomir for finding the needle in the haystack.

Move display of audio muted, video muted, and moderator icons,
which make up the elements of the small video toolbar, into React
Components.

* feat(avatar): SmallVideo uses the existing Avatar component.

On mobile we got the extra step of overriding the option and always set it to
true.

* feat(display-name): convert to React

- Create a new React Component for displaying and updating display
  names on small videos
- The updating of the Component is defined in the parent class
  SmallVideo, which children will get access to through prototype
  copying
- Create a new actionType and middleware so name changes that occur
  in DisplayName can be propogated to outside redux
- Update the local video's DisplayName when a conference is joined
  or else the component may keep an undefined user id

* squash: query for the container, not the el owned by react

This makes it possible for the following URL params to work:

config.p2p.enabled=true&config.p2p.preferH264=true

- Create a new ConnectionIndicator component for displaying an
  icon for connection quality and for triggering a popover. The
  popover handling has been left in ConnectionIndicator for now,
  which follows the existing implementation.
- Remove the unused method "connectionIndicatorShowMore"
- Change the implementation of existing methods that update the
  connection indicator to call the same method which will rerender
  the indicator completely.

- Add tracks to the redux store by intercepting where the
  tracks actually get used via conference.replaceTrack
- While the replace call is unique to web, the _dispose and
 _addTracks calls use existing native code implementations
- Between _dispose and addTracks is a call to update mute state.
  Without it, when changing devices or videoType while muted,
  the user will stay muted (whereas existing web behavior
  causes unmute). This is due to middelware calling
  _syncTrackMutedState to make the track mute if the user is
  currently muted.
- Move the rest of ConferenceEvents.TRACK_MUTE_CHANGED into
  middleware so the event is no longer used
- Note: This change does not guarantee the track state in the
  redux store will be 100% accurate, specifically the attribute
  videoStarted. Muted and videoType should be accurate.

- Use actions trackAdded and trackRemoved to add and remove remote
  tracks from the redux store
- Emit out to non-react components on track added and removed in
  the track middleware
- Emit out to existing non-react components on track mute and
  video type changes

Move all logic related to displaying a table of connection stats to a React
Component. The actual parsing logic was modified as little as possible as the
focus is moving display to React.

TraceablePeerConnection argument is lib-jitsi-meet internal and the app
does not need to care.

- Create new React Components for RemoteVideoMenu and its
  buttons
- Remove existing menu creation from RemoteVideo
- Refactor RemoteVideo so all function binding happens once in
  the constructor, removing the need to rebind when updating
  the RemoteVideoMenu
- Allow popover to append and remove React Components from itself
- Refactor popover so post-popover creation calls are broken out and
  popover removal behavior is all done in one function.

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.

There were regressions in the form of JS errors in Filmstrip introduced
when the call/ring overlay was rewritten in React.

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.

Also expose this in the native SDKs.

It's obsolete now, since config is handled in Redux. Also add a "defaultUrl"
prop so emdedding applications can select what the default base URL is.

The value of inviteURL is derived from locationURL by removing the hash
and query/search params in order to make it fit for display and/or
public purposes. The Jitsi Meet SDK consumers do not fall into that
category and our intention is to provide them with the URL they used
with JitsiMeetView.openURL(URL) anyway.

Also rewrites to remove repetition. I'm not saying the new source code
is better really but at least I got to examine it and comment on some of
its weaknesses.

The current implementation doesn't use the API and Transport modules. This is
due to the fact that they are too tied to APP at the moment, which is web only.

Once API is refactored and moved into the Redux store this will be adjusted,
though it's unlikely that the lowest level React Native module (ExternalAPI)
changes drastically.

This commit also introduces a stopgap limitation of only allowing a single
instance for JitsiMeetView objects on both Android and iOS. React Native doesn't
really play well with having multiple instances of the same modules on the same
bridge, since they behave a bit like singletons. Even if we were to use multiple
bridges, some features depend on system-level global state, such as the
AVAudioSession mode or Android's immersive mode. Further attempts will be made
at lifting this limitation in the future, though.

Introduced in
96e83989a5
as part of a refactor + feature.

If there is no focused node inside the dialog we focus any of the available buttons, submit button is first.

Rewrite the non-React RingOverlay into the React Component CallOverlay
in a way which makes it easier to port to React Native.

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.