[Platform] Manhattan plot with Observable Plot

[gjmcn]

Description

Recreate the Manhattan plot on the study page using Observable Plot. The basic plot is straight forward, but the interaction is fiddlier since Plot has limited functionality for this. The solution implemented here adds an HTML overlay that includes a tooltip with no restrictions on its content.

This PR adds some reusable components for using Observable Plot on the platform. Using the top-level ObsPlot component avoids explicitly setting up the responsive container and overlay tooltip.

Notes:

• The tooltip is click-to-stick.
• The approach is not particularly complicated, but we should add a README with usage instructions to the folder once happy with the approach.

Possible improvements:

• Requiring resetEelement to undo fade/highlight of marks is ugly since repeating information passed to the mark.
• Add width options such as "responsive", fixed width and min-width. Currently width is always responsive.
• Put types into own file since ObsPlot props are mostly passed directly to ObsChart or ObsTooltip.
• Can remove some props from ObsTooltipRow? Wait until update Phewas plot since it has potentially long row values.
• Shouldn't have to manually pass width and height to Plot in the renderPlot function.
• Uncouple highlight/fade from tooltip since could feasibly want to highlight/fade when trigger some other action such as opening a drawer.

Issue: #3662
Deploy preview:

Type of change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

Checked on study page.

Checklist:

• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• I have made corresponding changes to the documentation