Change time window adjustment on Variant Report Component to rely on API calls

[flaneuse]

Currently, the Situation Report Component relies on front-end filtering to fetch the data for all time, and then filter to the date range selected.

With the added min_date and max_date parameters added to the backend (outbreak-info/outbreak.api#54) we want to switch those to API calls.

• By default, calculate min_date = today - 6 months and execute that on page load.
• When the user selects one of the preset buttons (1 year, all time, etc.) -- execute a new API call to change the date.
• If the user selects a date window by using the D3 brushing function to select a date, adjust the date to the range they selected and execute the new API call.
• For all date changes, ensure the date changes also adjust the routes, so when the user reloads the page, the API call correctly parses the min_date and/or max_date
• Catch errors, as needed.