Select correct Reolink device uid (#142864)

* Select correct device_uid

* Fix styling

* restructure

* Add test

* Update test_util.py

* Add explanation string

tests/components/reolink/conftest.py

@@ -77,6 +77,7 @@ def reolink_connect_class() -> Generator[MagicMock]:
         host_mock.check_new_firmware.return_value = False
         host_mock.unsubscribe.return_value = True
         host_mock.logout.return_value = True
+        host_mock.is_nvr = True
         host_mock.is_hub = False
         host_mock.mac_address = TEST_MAC
         host_mock.uid = TEST_UID