The maxLength is enforced by removing elements from the head of the
list.

It follows the form of poll -> json parse -> append,
Where append is defined in subclasses to add data from the new frame
to long-lived rolling arrays of data.

It accumulates CPU and Memory usage for the allocation as a whole as well
as by task.

UI: Stats trackers

When data is coming in live, the tooltip can get bogged down by updates
causing the tooltip to never make it under the mouse, which looks like
either lag or a bug.

A use-case specific line-chart for showing utilization metrics by
percent

UI: line chart

It encapsulates all the tracker, polling, and markup for this style
of metric.

In favor of the new primary-metric components

This solves two problems:

1. redundant trackers making redundant requests
2. trackers being obliterated as soon as the primary metric component
   is destroyed

It introduces a new problem where visiting more and more node and
allocation pages adds to an ever-growing list of trackers that can
assume lots of memory, but it solves the problem by using a
least-recently-used cache to limit the number of trackers tracked.

…tric

This is the best of three options

1. Users of stats trackers control polling (old method)
2. Stat tracker is stateful and has start/stop methods (like logging)
3. Stat trackers blindly throttle requests

This is the best option because it means N number of concurrent users of
a stats tracker can request polling without inundating the tracker with
redundant frames (or the network with redundant requests), but they also
don't have to coordinate amongst themselves to determine what state a
tracker should be in.

…graphs

UI: Stat charts everywhere

- Treat it as an image
- Add a title and a description
- Hide the axes, just in case

Since this is a use case specific chart, we can use use case specific
language in our labels.

…esource-rows

UI: Use stats trackers for resource rows

UI: Add some simple accessibility labels for line charts