getLocalParticipant returns a participant object stored in Redux, not a
JitsiParticipant object.

* Add participantRoleChanged event to external API

* Update API documentation

* Remove unneeded whitespace

* Remove more unneeded whitespace

* Fix jsdoc formatting

* Fix jsdoc formatting

Refs: https://github.com/jitsi/lib-jitsi-meet/pull/1108

It's been considered too disruptive and will often misfire especially
if there are issues with the data channels.

It's an evolution of audio-only mode, where we also allow for receiving a remote
screen-share.

Diving deeper: this basically sets last N to 1 or 0 depending on the
availability of a screen-share.

This refactors all handling of audio-only and last N to 2 features in preparation
for "low bandwidth mode".

The main motivation to do this is that lastN is a "global" setting so it helps
to have all processing for it in a single place.

Otherwise the participant will not have been added yet
to state so the participant name will not display in
the notification.

Also, use the helper function to get the display name for a participant.

* Updates kick showing who kicked us.

* Notify participants that someone was kicked.

* Shows notification to user who is remotely muted.

* Updates the notification type.

* Muted by notification for mobile.

* Moves code to react and adds the kick notifications to mobile.

* Updates lib-jitsi-meet.

Using anything non-serializable for action types is discouraged:
https://redux.js.org/faq/actions#actions

In fact, this is the Flow definition for dispatching actions:

declare export type DispatchAPI<A> = (action: A) => A;
declare export type Dispatch<A: { type: $Subtype<string> }> = DispatchAPI<A>;

Note how the `type` field is defined as a subtype of string, which Symbol isn’t.

Updating react-native-fast-image brings a couple of interesting changes:

- onLoad is not called for cached images (reported and ignored upstream)
- load progress not working if component not displayed (on Android)

In order to fix this, a combination of 2 approaches was used:

- onLoadEnd / onError are used to detect if the image is loaded
- off-screen rendering is used on Android to get progress events

While implementing the above, yours truly noticed the complexity was increasing
way too much, so some extra refactoring was also performed:

- componentWillReceiveProps is dropped
- an auxiliary component (AvatarContent) is used for the actual content of the
  Avatar, with the former passing the key prop to the latter

Using the key prop ensures AvatarContent will be recreated if the URI changes,
which is not a bad idea anyway, since the new image needs to be downloaded.

Filmstrip remote thumbnails display under certain conditions, as
defined in filmstrip/functions.web.js. Previously the raw
participant count was used, which included fake participants.
Using the selector getParticipantCount excludes fake participants,
causing YouTube thumbnails to remain hidden in a 1-on-1 call.

It was moved to js-utils, so make use of it.

Use react-native-fastimage, which uses 2 full-native image impleentations using
well known and mature (native) libraries.

This gets us rid of 2 libraries which were observerd as a source of bugs and
created trouble with dependencies: react-native-fetch-blob and
react-native-img-cache. They are also no longer well maintained.

The Image adds a fade effect without asking, so lets explicitly disable
it. More info here:
https://github.com/facebook/react-native/issues/10194

* [WEB] add UI for transcription

* add analytics event for button, do not use global APP object

* use props instead of state, use local conference to kick participant

* put imports in alphabetical order

* add translation for TranscribingLabel

* fix merge conflict

* add closed caption button

* purge OverFlowMenuItem which starts and stops Transcription

* readd closed caption icon and fix small issues due to purge

* delete unused icon in _font.scss

BaseApp does all the heavy-lifting related to creating the redux store,
navigation, and so on.

App currently handles URL props and actually triggering navigation based on
them.