Previously we would retry push notifications indefinitely for all errors
except for ExpiredSubscription
Under certain conditions other persistent errors may arise such as a persistent
rate limit.
If we track more than 3 errors in a period of time longer than a day we will
delete the subscription
Also performs a bit of internal cleanup to ensure protected methods really
are private.
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
* Feature: Push notifications for Android
Notification config for desktop and mobile are merged.
Desktop notifications stay as they are for desktop views.
If mobile mode, push notifications are enabled.
Added push notification subscriptions in their own table, rather than through
custom fields.
Notification banner prompts appear for both mobile and desktop when enabled.
