* Additional setting to add search to speaker stats

* Add translation for speaker stats search placeholder

* Unset speaker stats search input autocomplete

* Fix lint errors for speaker stats search

* Change setting to disableSpeakerStatsSearch

* Better Object.prototype.hasOwnProperty.call alternative

* Make SpeakerStatsSearch a functional component

* Align header with input and use material-ui styles instead of scss and remove SpeakerStats header and fix dialog close

* Resolve code style remark in SpeakerStats constructor

* Resolve component empty return value remark in SpeakerStatsSearch

* Resolve get config property in outside function remark in SpeakerStatsSearch

* Resolve unnecessary anonymous function remark in SpeakerStatsSearch

For the most part the changes are taking the "static propTypes" declaration off
of components and declaring them as Flow types. Sometimes to support flow some
method signatures had to be added. There are some exceptions in which more had
to be done to tame the beast:
- AbstractVideoTrack: put in additional truthy checks for videoTrack.
- Video: add truthy checks for the _videoElement ref.
- shouldRenderVideoTrack function: Some component could pass null for the
  videoTrack argument and Flow wanted that called out explicitly.
- DisplayName: Add a truthy check for the input ref before acting on it.
- NumbersList: Move array checks inline for Flow to comprehend array methods
  could be called. Add type checks in the Object.entries loop as the value is
  assumed to be a mixed type by Flow.
- AbstractToolbarButton: add additional truthy check for passed in type.

Will override email, display name and avatar URL with the values
provided in 'context.user' structure of the JWT token.

Settings will no longer be used to retrieve local display name,
email and avatar URL. Now those values will be obtained from
the /features/base/participants Redux state.

fix(jwt/middleware): use const for default name

fix: wrong default display name on web

ref(base/participants): remove getDisplayName functions

ref(jwt): do not accept unknown user fields

Prepare for React 16.