[V2] Save templates to the database

[zdeveloper]

Save Templates to Backend

Acceptance Criteria

• Create POST /templates endpoint in backend
• Connect the frontend to use the templates crud api rather than local storage
• Creating a Template on the frontend should use the new API to store it on the backend

Testing Criteria

• Mock out API call on the front end.

[schreiaj]

This has been unblocked by #420 as the template now exists in a single structure.

However, merging this code prior to having the API/DB layer deployed would break demoing