Campaign data is now accessible in App Store - we can see new installs, impressions and data sharing opt-in rates by date. This resolves part of the outstanding issue in this ticket - however we still need to investigate tracking new installs by campaign in our own (potential) ios_install_referrer_event schema.

Context:
Because we are only able to see counts from App Store console and actions in ios_reading_lists we don't have a way to link the 2 data points. In short the App Store gives us a baseline. We can see users who are new doing Reading Lists actions by joining ios_reading_lists data with ios_user_history data, but there will not be an actual identifying link between App Store and our internal data. An ios_install_referrer_event event will surface the assigned app_install_id so we can properly track actions.