Add local notification for referee of referral program

[hesterbruikman]

Problem

When a user has onboarded through a referral url they receive a Starter pack. To improve retention, we want to notify users once they have received their Starter pack.

Implementation

Cannot use Push notifications (Google Play Services introduces issues for F-droid build)

Acceptance Criteria

User receives notification when:

• Used referral url to install and onboard to Status
• Opened url from Android
• Downloaded Status from Play store
• Accepted T&C of referral program and release of Starter pack (and referral bonus for referrer)
• Starter pack tx has been received

Notes

Previously discussed option was for referral service to send message from a private key that would trigger a local notification as per current implementation

Future Steps

[hesterbruikman]

cc @andremedeiros @Ferossgp @Samyoul

[hesterbruikman]

Covered by local notifications for tx and #11256