refs: https://github.com/jitsi/jitsi-meet/issues/4871

They never worked on mobile and pose an impediment for makinf config.js more
future proof. Specially if we want to move to a non-executable form of
configuration.

React Native doesn't define __filename nor __dirname so do it artisanally. In
addition, this helps with centralizing the configuration passed to loggers.

This prevents inserting any user overridden APP_NAME
values into html. A new translation key is being used
to immediately stop non-english languages from using the
problematic string.

Also tweaked the copy to remove the "eer" and fix
some grammar.

Pretend we have left instead of triggering a call failure. The user was already
told in the dialog.

* Configurable (sub)optimal and unsupported browsers

* maybe this helps somehow

* 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.

The welcomePageEnabled and pictureInPictureEnabled props on mobile have been
converted to feature flags.

When in a conference, try to enter PiP when pressing the back button. If this is
not possible (because it's unsupported, not enabled, etc.) fall back to the
previous behavior of simply hanging up.

This PR changes the logic for connecting / disconnecting conferences. Instead of
doing it in mount / unmount events from the Conference component, it moves the
logic to the appNavigatee action.

This fixes a regression introduced in 774c5ecd when trying to make sure the
conference terminated event is always sent.

By moving the logic to appNavigate we no longer depend on side-effects for
connecting / disconnecting, and the code should be more maintainable moving
forward.

An improvement to this is the concept of sessions, which, while not tackled
here, was taken into consideration.

Dear reader, I'm not proud at all of what you are about to read, but sometimes
life just gives you lemons, so enjoy some lemonade!

Joining a conference implies first creating the XMPP connection and then joining
the MUC. It's very possible the XMPP connection was made but there was no chance
for the conference to be created.

This patch fixes this case by artificially genrating a conference terminated
event in such case. In order to have all the necessary knowledge for this event
to be sent the connection now keeps track of the conference that runs it.

In addition, there is an even more obscure corner case: it's not impossible to
try to disconnect when there is not even a connection. This was fixed by
creating a fake disconnect event. Alas the location URL is lost at this point,
but it's better than nothing I guess.

This reverts commit 9625be1db3.

Adds 1 liner notifications to mobile. Only the title is displayed. In
case the title is missing there's a fallback to the description.

🔥🔥🔥

- unpin participant (if the local one was pinned it would remain)
- close any dialog (except if authentication is pending)

Co-authored-by: DimaG <dgeorgiev06@gmail.com>

Provide a default and builtin default implementation which finishes the
Activity, same as before.

What this PR removes is the ability to provide a custom default handler because
applications can already take this decision when calling `onBackPressed`. In
addition, make `onBackPressed` return `void` because it's virtually impossible
for it to return `false` (that would mean that there is no
`ReactInstanceManager`, which means there is no app to begin with).

In addition, remove the use of `BackAndroid` since `BackHandler` contains an iOS
shim now.

- Reset some state on the singletons conference
  and VideoLayout.
- Add a way for LocalVideo to clean itself up
  by sharing logic with the other SmallVideos.
- Add clearing of chat messages so they don't
  linger.
- Remove some UI event listeners.

- Change "features/chat" to support listening for new chat messages
  and storing them, removing that logic from conference.js.
- Combine chat.scss and side_toolbar_container.css, and remove unused
  scss files. Chat is the only side panel so the two concepts have
  been merged.
- Remove direct access to the chat feature from non-react and non-redux
  flows.
- Modify the i18n translate function to take in an options object.
  By default the option "wait" is set to true, but that causes
  components to mount after the parent has been notified of
  an update, which means autoscrolling down to the latest rendered
  messages does not work. With "wait" set to false, the children
  will mount and then the parent will trigger componentDidUpdate.
- Create react components for chat. Chat is the side panel
  plus the entiren chat feature. ChatInput is a child of Chat and
  is used for composing messages. ChatMessage displays one message
  and extends PureComponent to limit re-renders.
- Fix a bug where the toolbar was not showing automatically when
  chat is closed and a new message is received.
- Import react-transition-group to time the animation of the
  side panel showing/hiding and unmounting the Chat component.
  This gets around the issue of having to control autofocus if the
  component were always mounted and visibility toggled, but
  introduces not being able to store previous scroll state
  (without additional work or re-work).