Repair a handful of issues related to loading/rendering large DAGs in Dagit.
- The async layout WebWorker appears to be broken in development. This looks like it is related to a dependency issue in the worker file, which is ironed out here (titleOfIO). See comment below.
- Stop using fetch-and-network when querying for solids. These should be static anyway. There is an issue where the page gets into a query loop and never stops trying to update especially large DAGs. I'm still not quite sure what's triggering the loop, but we don't need to do more fetches after the first query anyway. (cc @alangenfeld re: our IRL discussion)
- Refactor PipelineExplorer to make use of React.useMemo and thus avoid some unwanted extra rendering.
- Some other implementation cleanup/changes that I made while trying to track down bugs.
- Show a message when attempting to render a very large number of solids, based on whether we have to use the WebWorker to do so.