Add legend to the radar

[partly-igor]

Description

Our Radar component needs a legend so that viewers can better understand what the colors on the radar map mean.

Radar legend mockups

Radar legend documentation

The legend should be added below the Radar and where where the Radar component appears – currently on the "Current" tab and on the "Alerts" tab when it appears.

Questions and Considerations

Noted in the documentation, I created an individual gradient element for each row of the table, rather than creating one single gradient. This way if the height of the row changes, the correct colors range is still contained within that row.

Acceptance Criteria

• Legend is added below the Radar on the "Current" tab
• Legend is added below the Radar on the "Alerts" tab