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.

The counterpart of the external API in the Jitsi Meet Web app uses the
search URL param jwt to heuristically detect that the Web app is very
likely embedded (as an iframe) and, consequently, needs to forcefully
enable itself. It was looking at whether there was a JSON Web Token
(JWT) but that logic got broken when the JWT support was rewritten
because the check started happening before the search URL param jwt was
parsed.

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.

* fix(vertical-filmstrip): different label animations for filmstrip states

Instead of one timing for sliding the video status label left and right,
have different timings depending on the filmstrip state. To facilitate
triggering the different animations, add more classes to the labels
that need to move that specify the filmstrip state.

- Faster transition if focusing on self-view with videos present so
  the label does not overlap videos transitioning from 0 opacity.
- Transition delay when de-focusing on self-view with videos present
  so videos have time to go away before the label moves over them.
- Maintain no movement if there are no videos, regardless of
  filmstrip toggle state.
- Different delays for when the filmstrip is being toggled visible
  and hidden if there are remote videos visible.

* SQUASH: remove remote videos count

* SQUASH: add docs to scss

The video status labels, which include recording and hd status,
have been moved back to the top left while in vertical filmstrip
mode. The following had to be done:
- Remove styling to move the labels to the bottom left
- For VideoStatusLabel, move filmstrip remote video count, toggle
  state, and 1:1 state into redux.
- Use middleware to emit out to the Recording label when the
  filmstrip changes.
- Create an empty Filmstrip file for web and identify the existing
  Filmstrip component as native.

The 1:1 call UI and vertical filmstrip act on remote videos
while leaving local video alone. To facilitate acting only on
remote videos, place remote videos into their own container element.

Audio only mode will be toggleable only from the VideoStatusLabel,
so remove AudioOnlyButton from the toolbar and delete the component
itself. As a result of the button being removed, a truthy check in
VideoStatusLabel was also removed to ensure it will display as it
is now the only way to toggle audio only mode. Also set the cursor
on VideoStatusLabel to always be default, so it can never show the
text cursor.

Add a menu that displays when hovering over VideoStatusLabel. The menu's
display is controlled by CSS. As the existing AudioOnlyLabel no longer needs
needs its own tooltip, it has been removed and label display logic has been
moved into VideoStatusLabel.

DialInNumbersForm has been modified to display a conference id to be used for
dialing into the conference. The changes include:
- Requesting the conference id and adding the conference id to the redux store
- Displaying the conference id in DialInNumbersForm
- Modifying the copy behavior to support copying the new message to clipboard
- DialInNumbersForm does not display until all ajax requests have completed
  successfully. This eliminates the need for the REQUESTING state.

In its current implementation, the VideoStatusLabel shows HD based on peer
connection stats. These stats will be available on temasys browsers soon but
will remain unavailable on Firefox, which does not collect height/width stats.
To support VideoStatusLabel showing cross-browser, move the high-definition
detection out of stat sniffing and instead check the video element itself using
an interval in LargeVideoManager. (An interval was used because the temasys
video object does not support the onresize event.) Also, add a cleanup path from
conference.web to LargeVideoManager to remove the interval.

There were getDomain, setDomain, SET_DOMAIN, setRoomURL, SET_ROOM_URL
which together were repeating one and the same information and in the
case of the 'room URL' abstraction was not 100% accurate because it
would exist even when there was no room. Replace them all with a
'location URL' abstraction which exists with or without a room.

Then the 'room URL' abstraction was not used in (mobile) feature
share-room. Use the 'location URL' there now.

Finally, removes source code duplication in supporting the Web
application context root.

Make 'Add jwt module to react' work on mobile.

Device selection has live previews that reuse the current local
audio and video tracks for the sake of internet explorer. This
means when the local video was muted, device selection would
show a muted message. It is preferred to show a live preview
even when muted.

The changes include:
- Passing device ids into DeviceSelectionDialog, not tracks.
- Setting default selected devices to use for live previews.
- Removing all checks in DeviceSelectionDialog involving local tracks.
- Catching and displaying errors when creating a live video preview.

Move the HD label into the newly renamed VideoStatusLabel
component. That way it cannot be possible for the audio only
label and the HD label to display simultaneously.

Audio only mode can be used to save bandwidth. In this mode local video is muted
and last N is set to 0, thus disabling all remote video.

When this mode is enabled avatars are shown.

* fix(react/participant): store display name in redux

* feat(remotecontrol): Add option to display the authorization dialog in meet

* feat(remotecontrol): Enable ESLint and Flow

toolbox/functions has functions that are specific only to web,
specifically defaultToolbarButtons. This has caused the native
build to attempt to bring in a web dependency which leads to a
build error. The fix for now is splitting web functions from
native functions to resolve the build error.

Create a new React Component for displaying a list of dial-in
numbers. The Component will fetch the numbers from a new
numberRetreviewUrl key/value set in config. If not present in
config, the Component will not be displayed.

Improves naming.
Fixing typos.
enableLegacyFormat param was working like disableLegacyFormat.
Improves the structure of transport/index.js

The transport module will be handling all external app
communication.