Add BarcodeFormat to result

#76 Fixed screen going black after hot reload.

# Conflicts:
#	android/src/main/kotlin/net/touchcapture/qr/flutterqr/QRView.kt

Fixed rotation on iOS.

Update example/README.md's code example

132 embedding v2

Updated Kotlin, Gradle & SDK versions.

Add cutout bottom offset

Properly implement ActivityLifecycleCallbacks public functions

Fixing bug I encountered (Unit defined in android.app.Application.ActivityLifecycleCallbacks)

e: C:\src\flutter.pub-cache\hosted\pub.dartlang.org\qr_code_scanner-0.0.14\android\src\main\kotlin\net\touchcapture\qr\flutterqr\QRView.kt: (41, 77): Object is not abstract and does not implement abstract member public abstract fun onActivityPaused(@nonnull p0: Activity): Unit defined in android.app.Application.ActivityLifecycleCallbacks
e: C:\src\flutter.pub-cache\hosted\pub.dartlang.org\qr_code_scanner-0.0.14\android\src\main\kotlin\net\touchcapture\qr\flutterqr\QRView.kt: (42, 13): 'onActivityPaused' overrides nothing
e: C:\src\flutter.pub-cache\hosted\pub.dartlang.org\qr_code_scanner-0.0.14\android\src\main\kotlin\net\touchcapture\qr\flutterqr\QRView.kt: (48, 13): 'onActivityResumed' overrides nothing
e: C:\src\flutter.pub-cache\hosted\pub.dartlang.org\qr_code_scanner-0.0.14\android\src\main\kotlin\net\touchcapture\qr\flutterqr\QRView.kt: (54, 13): 'onActivityStarted' overrides nothing
e: C:\src\flutter.pub-cache\hosted\pub.dartlang.org\qr_code_scanner-0.0.14\android\src\main\kotlin\net\touchcapture\qr\flutterqr\QRView.kt: (57, 13): 'onActivityDestroyed' overrides nothing
e: C:\src\flutter.pub-cache\hosted\pub.dartlang.org\qr_code_scanner-0.0.14\android\src\main\kotlin\net\touchcapture\qr\flutterqr\QRView.kt: (60, 13): 'onActivitySaveInstanceState' overrides nothing
e: C:\src\flutter.pub-cache\hosted\pub.dartlang.org\qr_code_scanner-0.0.14\android\src\main\kotlin\net\touchcapture\qr\flutterqr\QRView.kt: (63, 13): 'onActivityStopped' overrides nothing
e: C:\src\flutter.pub-cache\hosted\pub.dartlang.org\qr_code_scanner-0.0.14\android\src\main\kotlin\net\touchcapture\qr\flutterqr\QRView.kt: (66, 13): 'onActivityCreated' overrides nothing

replace var to let

The example is copied verbatim from ./example/lib/main.dart

For Android people it's not obvious why app crashes.