Add classic line charts

As nice as the existing dynamic widgets are, in certain cases it would be helpful to have classic line charts instead of the shiny dynamic bar charts. This would allow tracking changes better over time and take a screenshot for documentation. An example use-case is when debugging memory leak issues like described in https://stackoverflow.com/questions/64046973/dask-memory-leakage-issue-with-json-and-requests/64059237#64059237. I have attached the GIF used there here as well.