[dagit] Don't disappear Daemon statuses when loading
Since we're using network-only and hiding Daemon statuses when the query data isn't available yet, the table disappears and reappears a little too often.
@sashank, is there any cause for concern with changing this query to cache-and-network? I don't remember if there's anything related to your GRPC changes.
Instead, use cache-and-network to hang on to data that we have while refetching, and render a spinner when loading is in progress.
Test Plan: View /instance, use repository location reload and the countdown refresh. Verify rendering and behavior described above.
Reviewed By: sashank
Differential Revision: https://dagster.phacility.com/D5888