Allow to use the newly available execution time for testcases in html reports

Current situation

We now have a new datapoint for testcases, their execution time in ms. We use those in the XML reports the insight collector produces.

This datapoint can already be used in table columns, but we need extra 'graphical' views representing it. Things like barcharts, for example.

There should be a new BarChart section, and there may be other new type of sections too.