Enable Common Cpp sources compilation and usage in NotificationService

Summary: NotificationService is an Application Extension and hence a separate XCode target so it needs its own Compile Sources definition. Moreover using UI - related API is not allow in application extension. Therefore in order to use some expo libraries (parts of which use UI API, but not the ones we use in NotificationService) I needed to programatically disable APPLICATION_EXTENSION_API_ONLY flag in Podfile.

Test Plan: Firstly succesfully compile iOS app for both release and debug version. Then place calls to methods from CommonCpp (SQLiteQueryExecutor in particular) inside NotificationService callback and send push notification to running app instance on physical device. Check whether CommonCpp is working inside NotificationService callbacks as expected.

Reviewers: palys-swm, ashoat, def-au1t, atul

Reviewed By: palys-swm, ashoat, def-au1t

Subscribers: benschac, def-au1t, ashoat, Adrian, atul, karol-bisztyga

Differential Revision: https://phabricator.ashoat.com/D3370