This encapsulates substantial logic to encapsulate interpretation of the
Crucible Common Data Model OpenSearch schema for the use of CPT dashboard API
components. By itself, it does nothing.

This builds on the `crucible_svc` layer in cloud-bulldozer#122 to add a backend API.

This relies on the ilab API in cloud-bulldozer#123, which in turn builds on the crucible
service in cloud-bulldozer#122.

When graphing metrics from two runs, the timestamps rarely align; so we add a
`relative` option to convert the absolute metric timestamps into relative
delta seconds from each run's start.

This adds the basic UI to support comparison of the metrics of two InstructLab
runs. This compares only the primary metrics of the two runs, in a relative
timeline graph.

This is backed by cloud-bulldozer#125, which is backed by cloud-bulldozer#124, which is backed by cloud-bulldozer#123,
which is backed by cloud-bulldozer#122. These represent a series of steps towards a complete
InstructLab UI and API, and will be reviewed and merged from cloud-bulldozer#122 forward.

This PR is primarily CPT dashboard backend API (and Crucible service) changes
to support pulling and displaying multiple Crucible metric statistics. Only
minor UI changes are included to support API changes. The remaining UI changes
to pull and display statistics will be pushed separately.

Add statistics charts for selected metric in row expansion and comparison
views.

Extract the "Metadata" into a separate component, which allows it to be reused
as an info flyover on the comparison page to help in identifying target runs
to be compared.

Modify the metrics pulldown to allow multiple selection. The statistical
summary chart and graph will show all selected metrics in addition to the
inherent benchmark primary benchmark (for the primary period).

Support selection of multiple metrics using the pulldown in the comparison
page. The update occurs when the pulldown closes.

To simplify the management of "available metrics" across multiple selected
runs, which might have entirely different metrics, the reducer no longer
tries to store separate metric selection lists for each run. This also means
that the "default" metrics selection remains when adding another comparison
run, or expanding another row.