Eliminate circular deps in dagit JS
I ran into some unexpected build failure oddities during development that looked like they might be related to circular dependencies in dagit JS, so I'm cleaning them up here. From what I can tell, eliminating these has successfully eliminated the build failures I was seeing.
I used https://github.com/pahen/madge to detect circular deps. I also enabled import/no-cycle in our eslint config.
Test Plan: Run madge, verify that no circular deps remain. Lint, ts, jest.
Reviewers: bengotow, alangenfeld, sashank
Reviewed By: sashank
Differential Revision: https://dagster.phacility.com/D4649