API: Permissions Design

[AzorianMatt]

Complete a functional design of an application permissions solution.

1. Create Pydantic model-based permissions architecture that provides permission metadata.
2. Create SQLAlchemy ORM model for storing permissions assignments in the SQL database.
3. Create permissions manager class to manage database storage and retrieval of permissions data.
4. Create permissions manager methods for validating resource / action access by users and OAuth clients.