Note that in the usual (vertical) setup, the "toolbar" is just the hide button.

* fix(thumbnail): Optimize status bar moderator icon

Moved all moderator functionality to react to optimize the number of
status bar updates.

* fix(RemoteVideoMenuTriggerButton): Use nullish coalescing

Co-Authored-By: Saúl Ibarra Corretgé <saghul@jitsi.org>

* ref(StatusBar): rename to StatusIndicators

* fix(RemoteVideoMenu): isModerator value.

* fix(notification): mobile.

Co-authored-by: Saúl Ibarra Corretgé <s@saghul.net>

* ref(Filmstrip): Optimize resizes.

* fix(thumbnails): resize.

* fix(thumbnails): Issue with height 0, width 0.

* doc(Filmstrip): Improve JSDoc.

Simplifies the code a bit, and we use no lifecycle methods.

Audio streams are automatically played by WebRTC and this won't change, probably
ever. There is no point in having checks and an Audio component which does
nothing.

🔥🔥🔥

Touch feedback manifests in some ugly black border bleeding out of the thumbnail
itself. Since we already provide feedback (be that by adding the blue border in
case of pinning, or showing the menu in case of long press) the perception is
the same, without the graphical glitch.

They are part of the Jitsi font now, there is no need to load them from
FontAwesome.

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.

* feat(tile-view): initial implementation for mobile

- Create a tile view component for displaying thumbnails in a
  two-dimensional grid.
- Update the existing TileViewButton so it shows a label in the
  overflow menu.
- Modify conference so it can display TileView while hiding
  Filmstrip.
- Modify Thumbnail so its width/height can be set and to prevent
  pinning while in tile view mode.

* use style array for thumbnail styles

* change ternary to math.min for expressiveness

* use dimensiondetector

* pass explicit disableTint prop

* use makeAspectRatioAware instead of aspectRatio prop

* update docs

* fix docs again (fix laziest copy/paste job I've ever done)

* large-video: rename onPress prop to onClick

* change forEach to for...of

* use truthy check fallthrough logic instead of explicit if

* put tile view button second to last in menu

* move spacer to a constant

* the magical incantation to make flow shut up

* feat(tile-view): initial implementation for tile view

- Modify the classname on the app root so layout can adjust
  depending on the desired layout mode--vertical filmstrip,
  horizontal filmstrip, and tile view.
- Create a button for toggling tile view.
- Add a StateListenerRegistry to automatically update the
  selected participant and max receiver frame height on tile
  view toggle.
- Rezise thumbnails when switching in and out of tile view.
- Move the local video when switching in and out of tile view.
- Update reactified pieces of thumbnails when switching in and
  out of tile view.
- Cap the max receiver video quality in tile view based on tile
  size.
- Use CSS to hide UI components that should not display in tile
  view.
- Signal follow me changes.

* change local video id for tests

* change approach: leverage more css

* squash: fix some formatting

* squash: prevent pinning, hide pin border in tile view

* squash: change logic for maxReceiverQuality due to sidestepping resizing logic

* squash: fix typo, columns configurable, remove unused constants

* squash: resize with js again

* squash: use yana's math for calculating tile size

* ref(filmstrip): create an empty container for local filmstrip move

This might be necessary for tile view. To support making the
local video display at the end of remote videos while in tile
view, but separateed from scrollable remote videos, moving
the local video might be necessary. By creating an empty
container, there is a target for local video to move to.

* squash: rename id

Very likely I broke something subtle and I'm prepared to fix it.

This zOrder change fixes the issue that the scrollable filmstrip videos
rendered in front of the local participant, however there is still an
issue that needs to be fixed later: The rendered videos should have
overflow: 'hidden' property applied so then they don't get rendered when
scrolled out of the ScrollView, that property however doesn't seem to
work for Video components.

- 5 buttons in the (now single) toolbar
- Overflow menu in the form of a BottomSheet
- Filmstrip on the right when in wide mode

Contributing all buttons in one place goes against the designs that we
set out at the beginning of the project's rewrite and that multiple of
us have been following since then.

- Move the toolbar to the filmstrip feature
- Use all the buttons from the toolbox feature

* Separate local thumbnail in filmstrip

* style(Filmstrip.native): utilize full line length

This PR takes The Bulldozer Approach (R): removes the old toolbox and lots of
associated code, though not all of it. Subsequent cleanups will follow.