1. Aligns the project structure of Jitsi Meet SDK for iOS with that for
   Android for better comprehension.

2. The command `react-native run-ios` uses the last Xcode project or
   workspace in the list of these sorted in alphabetical order. Which
   limits our freedom in naming. Thus having only an Xcode project in
   the root directory of the iOS project structure gives us back the
   freedom in naming.

3. Allows the Podspec to work for the app project in addition to the sdk
   project because we need Crashlytics in the app which is integrated
   via Cocoapods as well.

4. Further removes references to JitsiKit in the source code for the
   sake of consistent naming.

As a step toward merging jitsi-meet-react with jitsi-meet to share as
much source code as possible between mobile and Web, merge the part of
jitsi-meet-react's source tree which supports mobile inside the
jitsi-meet source tree and leave jitsi-meet-react's Web support in the
source code revision history but don't have it in master anymore because
it's different from jitsi-meet's Web support. In other words, the two
projects are mechanically merged at the file level and don't really
share source code between mobile and Web.

As an intermediate step on the path to merging jitsi-meet and
jitsi-meet-react, import the whole source code of jitsi-meet-react as it
stands at
2f23d98424
i.e. the lastest master at the time of this import. No modifications are
applied to the imported source code in order to preserve a complete
snapshot of it in the repository of jitsi-meet and, thus, facilitate
comparison later on. Consequently, the source code of jitsi-meet and/or
jitsi-meet-react may not work. For example, jitsi-meet's jshint may be
unable to parse jitsi-meet-react's source code.