AAI-182 admin backend endpoints

[marius-mather]

Description

AAI-182: implement admin endpoints for the AAI backend, as described in https://docs.google.com/document/d/1W3-7Hme08M-b4kwMvcQoUscznVNxtOldxuKYPPRhBFE/edit?tab=t.0#heading=h.yiv7256z72hs

Changes

Routes implemented:

• /admin/users - get all users
• /admin/users/{user_id} - get a single user
• /admin/users/approved - get all users with approved services
• /admin/users/pending - get all users with pending service requests
• /admin/users/revoked - get all users with revoked services
• /admin/users/{user_id}/services/{service_id}/approve - approve a service
• /admin/users/{user_id}/services/{service_id}/revoke - revoke a service
• /admin/users/{user_id}/services/{service_id}/resources/{resource_id}/approve - approve a resource

Checklist

• I have commented my code, particularly in hard-to-understand areas
• I have added unit / integration tests that prove my fix is effective or that my feature works
• I have run all tests locally and they pass
• I have updated the documentation (if applicable)

How to Test Manually (if necessary)

Run uv run pytest

[amandazhuyilan]

Overall looks great - nick picks as usual...