Use Apollo cache normalization for schedule stop/start
Previously, the Dagit scheduler page would use optimistic updates to update the state of the schedule state toggle. This diff changes it to properly use Apollo's cache normalization for mutations.
Test Plan: Start and stop schedules from Dagit, verify they are in the correct state
Reviewers: #ft, prha
Reviewed By: #ft, prha
Differential Revision: https://dagster.phacility.com/D1384