[dagit] Fix sensor/schedule mutations
Summary: TypeScript allowed me to have name and status vars that didn't pull values from the GraphQL payload, so the sensor and schedule switches broke with https://dagster.phacility.com/D7839. This fixes the vars.
Test Plan: View sensor and schedule in Dagit. Turn them on/off, verify success and correct switch state after action.
Reviewers: bengotow, yuhan, prha
Reviewed By: yuhan, prha
Differential Revision: https://dagster.phacility.com/D7850