It significantly speeds up debug builds, putting them on par with Android, where
we also don't bundle the React resources.

With this the RN component and the consumer app can share same CallKit
provider, configuration, and enable to be part of multiple listeners of
the CallKit flow events. The main driver of this is to enable the
consumer app to be able to report an incoming call to the OS before
loading the JitsiMeetView. Once the user answers the call, the app can
instantiate a JitsiMeetView, pass the CallKit call UUIID, and the Jitsi
Meet components will handle the connection and report back to CallKit
that the  call has been established.

If the beginAddPeople delegate method is implemented, and they haven't been
explicitly set to NO, they willbe YES.

* Button conditionally shown based on if the feature is enabled and available
* Hooks for launching the invite UI (delegates to the native layer)
* Hooks for using the search and dial out checks from the native layer (calls back into JS)
* Hooks for handling sending invites and passing any failures back to the native layer
* Android and iOS handling for those hooks

Author: Ryan Peck <rpeck@atlassian.com>
Author: Eric Brynsvold <ebrynsvold@atlassian.com>

On Android the files will be copied to the assets/sounds directory of
the SDK bundle on build time. To play the "asset:/" prefix has to be
used to locate the files correctly.

On iOS each sound file must be added to the SDK's Xcode project in order
to be bundled correctly. To playback we need to know the path of the SDK
bundle which is now exposed by the AppInfo iOS module.

This only works automatically on Android >= 8. On other platforms / versions, it
relies on the SDK user on implementing a "reduced UI" mode and reacting to the
"request PIP" delegate method.

Story time.  Currently the app can be started in 4 ways:

- just tapping on the icon
- via a deep link
- via a universal link
- via the phone's recent calls list

The last 3 options will make the app join the specified room upon launch. React
Native's Linking module implements the necessary bits to handle deep or
universal linking, but CallKit is out of its scope.

In order to blend any type of app startup mode, a new LaunchOptions module (iOS
only) exports a getInitialURL function, akin to the one in the Linking module,
but taking CallKit instents into consideration. This function is then used to
make app startup with a URL consistent across all different modes.

Fixes: #2377 #2267 #2158

Due to the difference in nature, the iOS and Android implementations are
completely different:

iOS: MPVolumeView is used, which allows us to place a button which will launch a
native route picker provided by iOS itself. This view is different depending on
the iOS version, with the iOS 11 version being more complete.

Android: A completely custom component is used, which displays a bottom sheet
with the device categories, not devices individually. This is akin to the sheet
in the builtin dialer.

The root view was not adjusting it's bounds after device rotation.

Revert "[RN] Remove unnecessary source code" (commit
a3441030a3). But since the project file
needs to explicitly mention the CallKit and Intents framework, do not
use the semantic @import as that's confusing in the case.

CocoaPods has made some updates to the bundled resource files.

* Javadoc introduced @code as a replacement of <code> and <tt> which is
  better aligned with other javadoc tags such as @link. Use it in the
  Java source code. If we switch to Kotlin, then we'll definitely use
  Markdown.

* There are more uses of @code in the JavaScript source code than <tt>
  so use @code for the sake of consistency. Eventually, I'd rather we
  switch to Markdown because it's easier on my eyes.

* Xcode is plain confused by @code and @link. The Internet says that
  Xcode supports the backquote character to denote the beginning and end
  of a string of characters which should be formatted for display as
  code but it doesn't work for me. <tt> is not rendered at all. So use
  the backquote which is rendered itself. Hopefully, if we switch to
  Markdown, then it'll be common between JavaScript and Objective-C
  source code.

This commit adds initial support for CallKit on supported platforms: iOS >= 10.

Since the call flow in Jitsi Meet is basically making outgoing calls, only
outgoing call support is currently handled via CallKit.

Features:
 - "Green bar" when in a call.
 - Native CallKit view when tapping on the call label on the lock screen.
 - Support for audio muting from the native CallKit view.
 - Support for recent calls (audio-only calls logged as Audio calls, others show
   as Video calls).
 - Call display name is room name.
 - Graceful downgrade on systems without CallKit support.

Limitations:
 - Native CallKit view cannot be shown for audio-only calls (this is a CallKit
   limitaion).
 - The video button in the CallKit view will start a new video call to the same
   room, and terminate the previous one.
 - No support for call hold.

It provides access to the app's display name and version.

Based on work authored by Shuai Li <sli@atlassian.com>, Daniel Ornelas
<dornelas@atlassian.com>, and Lyubo Marinov <lmarinov@atlassian.com>.