Move all example apps to use "flutterfire-e2e-test" project

[russellwheatley]

1. Move all example apps to use "flutterfire-e2e-tests" project.
2. Ensure platforms (Web, macOS, iOS & Android) run fine on the example app (i.e. no exceptions occur when building/running application as Podfile/build.gradle needs updating and the API works as intended).

Some example apps will need the Flutter implementation updating when moving to "flutterfire-e2e-tests" project such as the Dynamic Link. It is associated with the "react-native-firebase-testing" project.

Plugins

Check the platform once it has been updated, it is running without issue & merged into "master" branch.

Firestore

• iOS
• Android
• macOS
• web

App Check

• iOS
• Android
• macOS
• web

Messaging

• iOS
• Android
• macOS
• web

Storage

• iOS
• Android
• macOS
• web

Remote Config

• iOS
• Android
• macOS
• web

Analytics

• iOS
• Android
• macOS
• web

Cloud Functions

• iOS
• Android
• macOS
• web

Auth

• iOS
• Android
• macOS
• web

App Installations

• iOS
• Android
• macOS
• web

Database

• iOS
• Android
• macOS
• web

Core

• iOS
• Android
• macOS
• web

Crashlytics

• iOS
• Android
• macOS

Dynamic Links

• iOS
• Android

In App Messaging

• iOS
• Android

Performance

• iOS
• Android
• web

Storage

• iOS
• Android
• macOS
• web