Payment trigger initial payment / finalized setting

[Klakurka]

An expansion onto #613, add a setting (to #619) for whether they would like a payment trigger notification when the payment is initially detected, upon 1 conf / finalization, or both.

We'll want to update the messages JSON to include something like "status": "payment received" or "status": "finalized" so they can easily differentiate them if they decide to choose "both" to avoid having them think they received 2 payments.