Add support for notification actions on iOS

We have to save initial notification action response
in case there isn't registered any FCMNotificationReceived
event handler yet. For example when the app is killed by a user
so JS has to be initialized first. The saved action
response will be sent to JS after first
FCMNotificationReceived event handler registered.

Add Pod paths to header search paths

By adding the pod paths, we ensure that if dependencies (namely React) are installed *only* via Pod and not via direct linking in the project.

Dispatch setApplicationIconBadgeNumber on main thread to prevent runtime warnings

Fix cocoapods react-native-fcm 11

fix pod install typo

This Requires cocoapods 1.4 to run
sudo gem install cocoapods --pre

fix fail notification schedule after reboot on Android

Update README about Android Configuration