[dagit] Remove config/playground affordances for Schedules
Summary: Remove options to view configuration or open a schedule in the playground, as these can just be done via the run and the pipeline.
Test Plan: Lint, jest, ts. View relevant pages on Dagit, verify proper rendering.
Reviewers: prha, dgibson, johann
Reviewed By: prha
Differential Revision: https://dagster.phacility.com/D5220