Refactor contact handling across backend and frontend

Replaced usage of "ContactPerson" with "Contact" for consistency across the codebase. Updated related component props, state variables, API calls, and database queries to align with the new model. Also enhanced backend functionality with stricter validations and added support for handling active pgroups in contact management.

backend/tests/test_auth.py

@@ -33,4 +33,7 @@ def test_protected_route():
     headers = {"Authorization": f"Bearer {token}"}
     response = client.get("/auth/protected-route", headers=headers)
     assert response.status_code == 200
-    assert response.json() == {"username": "testuser", "pgroups": [20000, 20001, 20003]}
+    assert response.json() == {
+        "username": "testuser",
+        "pgroups": [20000, 20001, 20002, 20003],
+    }