Adapt admin api to use new key format

Filter out deleted an previous version in count

Remove todo comment

Allow explicit ID specification

Update tests

tests/integration/test_backend.py

@@ -51,7 +51,7 @@ async def test_create_secret(backend_api: SshecretBackend) -> None:
     assert secret_to_client is not None
 
     assert secret_to_client.name == "mysecret"
-    assert "test" in secret_to_client.clients
+    assert secret_to_client.clients[0].name == "test"
 
     secret = await backend_api.get_client_secret("test", "mysecret")