3932 Move integration test to null safety for multiple plugins (cla: yes, p: webview_flutter, p: image_picker, p: in_app_purchase, p: wifi_info_flutter, p: quick_actions, p: connectivity, p: device_info, platform-ios, platform-android, platform-macos)

3971 Point deprecated plugins to Plus versions (cla: yes, p: battery, p: android_alarm_manager, p: android_intent, p: share, p: package_info, p: wifi_info_flutter, p: sensors, p: connectivity, p: device_info)