Define A New `ProviderService` Interface Implementation

[jtucholski]

Description

Create a new ProviderService interface implementation in the middleware, specifically for D2L Brightspace, that aligns with UnlockEd’s data model and supports future expandability for more LMS providers.

Tasks

• [ ] Design the ProviderService interface for Brightspace integration.
  • Define methods to handle user, course, and content data fetching.
  • Ensure the interface follows the same structure as existing provider services.
• [ ] Create a placeholder implementation for each method to allow future integration with Brightspace data sources.
• [ ] Document how this new interface will plug into the existing middleware and what external services or APIs it will rely on.

User stories

• As a backend developer, I want to create a ProviderService interface for Brightspace so that the UnlockEd middleware can easily sync educational data from Brightspace.

Acceptance criteria

• A fully defined ProviderService interface for Brightspace exists.

Notes

• This service should easily integrate with existing provider architecture in UnlockEd.

[jtucholski]

Depends on #428