Add a second option to visualize the data set - map view.

Ideally, there would be a date-controlling slider and animation.

User could select one or more districts wich would create a plot of time-series for the selected districts.

ÚZIS started publishing data on district level with version 2 of its API. This data is published with a delay of around 7 days so it is not suitable as a primary data source.

However, it would be nice to add ÚZIS data as a secondary data source and enable users to switch between primary and secondary data source.

Advantages

1. Users could compare reliability of primary data source be comparing it to the official data set published by ÚZIS.
2. We could add new time series - recovered, currently ill, dead.

The current implementation of the app is cpu intensive. The graphs is re-plotted whenever the users changes the selection of districts in the table.

For some reason, the plotting is quite resource-intensive (cpu). There might be several ways how to improve plotting performance:

1. Switch to client-side callbacks
2. Abandon plotly-express and use just plotly