Dev: Suspend callbacks backend

[whabanks]

Description

As a Notify Team Member, I need to be made aware of callback failures via alarms so that I can take appropriate action to warn a service owner or suspend their callback functionality.

As a Notify Dev doing front end working, I need back end plumbing in place so that I can retrieve and update the suspension status of a service's callbacks.

Acceptance Criteria

• Warning and Critical alarms are created/updated in Terraform. (Update and add callback alarms notification-terraform#1507)
  • Agree on less sensitive alarm thresholds from the ADR
• Add admin code to suspend a callback through the setting page
• Add API code to take is_suspended into account and not send the Callback
• Add suspended and suspended_at columns to the service_callback_api table
• Update ServiceCallbackApi model & associated schemas in API
• Add new API endpoint to set suspended and suspended_at when suspending or resuming a callback.

[yaelberger-commits]

Hey team! Please add your planning poker estimate with Zenhub @andrewleith @jzbahrai @whabanks

[yaelberger-commits]

Will & Jumana are each working on their own parts of this work today

[yaelberger-commits]

@jzbahrai has an Admin PR open, and an API PR open, both need reviews from Will

[yaelberger-commits]

API code needs to be merged, and Will's PR. Should get merged today

[yaelberger-commits]

PR up for API code suspended check.
One more task for front-end to add a testing URL for the users, last AC

[yaelberger-commits]

API PR merged and released in Prod

[yaelberger-commits]

We now have the ability to suspend/resume a callback service for any client (manually)