performance issues on targets/tests and build views

[trey-ivy]

the invocation view is pretty performant overall, but as you scale the number of items in the database, the targets and tests views start to crawl. When you get a substantial number of steps in your build, the build view also starts to crawl and can become unresponsive.

target and test views:
refactor the graphql query on the backend to do less calculation and just dump results to speed things up. This might mean no pass percentage on the /targets or /tests views themselves and no pass/fail grid on that view, but we can just move that data into the details views and get things working overall much more smoothly

builds view:
there is no good reason why the builds view needs to include all the invocation details for every invocation in the build. I think it would work better if it was just a list of invocations with a tagline that contains some basic data (pass/fail, duration, etc.). If you want to drill in and view more, there is always the bazel-invocations/[slug] details view