[TASK] Stub Logo/Icon API endpoints on backend

[andyatmiami]

Certification

• I certify I am an Epic Owner for Kubeflow Notebooks 2.0 and expected to create planning-related issues.

Description

We want a stubbed implementation of the Logo/Icon API as outlined in #689 .

Definition of a "stubbed implementation":

• Changes are expected to be delivered under following folders:
  • workspaces/backend/api
  • workspaces/backend/internal/models
  • workspaces/backend/openapi
    • ℹ️ files under this directory are auto-generated from swag Makefile command
• Data returned by the API should be hard-coded and provide a minimally viable experience for the frontend to be able to exercise the API!
• Changes should NOT be provided in workspaces/backend/internal/repositories
  • These changes would be included when working on the real implementation of the endpoints
• Basic unit testing should still be provided for the changes
  • These tests would obviously require asserting on the hard-coded "mock" responses and will require rework then when we implement these endpoints for real

Acceptance Criteria

• [ ]swagger.json includes all the appropriate metadata to expose APIs as outlined in [TASK] Agree on architecture/implementation details for logo/icon APIs #689

[andyatmiami]

/assign