Fix horizontal chart scrolling

[TaiWilkin]

Overview

After upgrading ChakraUI, the menu for the download menu was rendered but hidden prior to being opened. This caused a gap the width of the menu to appear to the right of the charts, resulting in charts scrolling horizontally even on full-screen (charts are expected to scroll on mobile only).

Rendering the menu list in a portal prevents the menu from effecting the page layout, fixing the horizontal scroll.

Connects #127

Demo

Horizontal Scroll:

No Scroll:

Testing Instructions

• On staging, select some geographies and a question of each type (agree/disagree, out of ten, other), then attempt to scroll right on a chart. You will see the chart scroll and a gap appear at the right. Open the download menu and the gap will vanish.
• In the Netlify preview for this branch, select some geographies and a question of each type (agree/disagree, out of ten, other), then attempt to scroll right on a chart. The chart should not scroll.
• Open and use the download menu for each chart type to confirm it works as expected.
• Use mobile view and confirm the charts still scroll. We do not fully support mobile, but users should be able to access the site and view the charts with scrolling.

[rajadain]

Taking a look now

[TaiWilkin]

Thank you for reviewing!