[dagit] Repair run tag overrides
In cases where a code-defined pipeline tag is overridden via the tag editor:
- Show the overridden tag as being overridden, with a lower opacity and a tooltip
- Ensure that the newly saved tag is actually applied to the run -- this is currently broken, because the updated session is not being applied to the execution button. This is due to a React render short-circuit, which keeps getVariables bound to a stale session object.
View the playground for a pipeline with a code-defined tag.
- Verify that the tag shows up correctly in the playground.
- Override it with the tag editor. Verify that the overridden tag is displayed accordingly. Save.
- Verify that the overridden tag and the override tag both appear in the tag list on the playground, with the low-opacity/tooltip display on the overridden tag.
- Kick off a run. Verify that the generated run has the overridden tag applied to it.
Reviewers: bengotow, alangenfeld, prha
Reviewed By: alangenfeld
Differential Revision: https://dagster.phacility.com/D8118