GET localhost:8000/api/v1/ilab/runs?benchmark=ilab will query the
ilab.crucible OpenSearch instance and return a list of ilab benchmark
runs.

Add Crucible readme file.

Cleanups and refactoring

Also added the option to override the default graph title generator using the
new `Graph.title` field.

This cleans up my direct API call to get the run's periods for graphing, to
use a separate action and a reducer.

I also experimented with trying to improve error diagnosis by looking at some
of the error responses to "toast" instead of just saying something went wrong.

Add a Crucible `close` method, and use a FastAPI yield dependency to ensure
every API connection is closed cleanly.

+ other review feedback

+ add some method documentation
+ misc review feedback

Multigraph API failed if more than one `Graph` element specified the same run;
fix to be smarter about missing run IDs.

This also contains experimental code to expose per-iteration param values,
which doesn't quite work but doesn't seem to hurt anything.

(And `/api/v1/ilab/runs` reports iterations in numerical order.)

Move the legend up off the graph (although 1.5 is arbitrary and maybe not
ideal -- is there a more dynamic way to do this).

Also, I fixed the name of a `.less` class earlier, but just happened to notice
the corresponding use...

Move "unique parameters" accordion back up with parameters using the new
expansion toggles.