add charts to display some time series data

[ebrahimebrahim]

Add a chart display to show time series data such as ventilator parameters

e.g. we can use chart.js

This depends on #9 being completed, so that we have a source of time series data. It also depends on #14 being completed so that there is a suitable place to display the chart.

[ebrahimebrahim]

Clinicians will probably be especially excited to see the charts showing time series. Especially supplemental O2, but also they say it will be nice to be able to select any time series data and see it in the chart view, and even stack multiple in the same view.