Supermind expiring soon push & in-app notifications

Goal

Trigger push & in-app notifications when a supermind request is expiring soon.

What needs to be done

Connect the notification work done in #2409 (closed) with the expiring soon cronjob work done in #2432 (closed). Both of these issues should be completed before starting this one.

Probably by linking the push notifs stuff with the ACTION_SUPERMIND_REQUEST_EXPIRING_SOON event consumed in SupermindEventStreamsSubscription.php

QA

make sure the notifications send

UX/Design

n/a

Personas

supermind users

Experiments

supermind experiment

Acceptance Criteria

• in-app notification sent when supermind expiring soon
• push notification sent when supermind expiring soon

Definition of Ready Checklist

• Definition Of Done (DoD)
• Acceptance criteria
• Weighted
• QA
• UX/Design
• Personas
• Experiments