EXPLORE: Allow API users to create templates without using Admin

Description

As a GC Notify API user, I need to be able to add templates using the API so that I can send notifications without needing to log into GC Notify and using the UI.

It would also be nice if the API could grab the template from the application for transactional notifications

WHY are we building? We've been asked by clients if they can add templates through the API, but for now they need to create their templates in the UI only. WHAT are we building? A way to add templates via the API VALUE created by our solution Less friction for API users, a more robust API for automated sending and more interoperability with applications used for managing benefits and services.

Documentation and Artifacts

Good docs, figma mockups, ADRs, screenshots etc.

Acceptance Criteria

Given some context, when (X) action occurs, then (Y) outcome is achieved

[ ] Cypress UI tests if needed.
[ ] Generate appropriate log messages so that executions of this feature can be tracked
[ ] Can misuse of this feature cause harm? If yes, create an alert
[ ] Update the status of related findings, insights, and hypotheses on the Research Airtable
[ ] Once change/fix/feature is implemented, link relevant Airtable records to design artifacts (Figma)
A11y
Bilingualism
Privacy considerations
Security controls in place
Measuring success and metrics

Related Research Airtable records

(Ping Adrianne to add stuff here or find stuff yourself)

QA Steps

[ ] Tested in a realistic production scenario

cds-snc / notification-planning