Currently openapi spec is generated from the code.
Investigate generating interfaces from the openapi then adding the implementation in current a1-pms.

Move to openapi-first approach.

This will make API documentation and testing alot easier.

Possible subtasks:

• Add alot more detail & example to paramaters & schemas

• Investigate a better way to describe callbacks/webhooks in openapi spec (e.g. ric status, authorization callouts, etc)