Problem:

coder/coder#17091 adds functionality for sending push notifications.

This is currently not well-integrated into the rest of the nofications system.
The current notifications system has a enqueue system, and the current use-case for push notification is for immediate delivery. The current enqueue-dispatch logic takes too long for these notifications to be effective and timely.

Ideally we would have a way to immediately dispatch a notification without enqueuing it. In this case, delivery could not be guaranteed, but that's the tradeoff.

Proposed solution:

Add the capability to enqueue a notification for immediate dispatch, bypassing the database entirely. If we are not able to immediately dispatch, simply return an error to the caller.