[Posting this here in order to check if no duplicates before GH issues]
Currently, the numerical visualization allows you to choose between 4 display types : normal, scientific, percentage and currency.
When we want to display a duration (like average time on website, average time for pull request merging, etc.) we have to go through a GUI-pain, which is to create customized columns containing the different strings needed ("minutes", "and", "seconds") in order to display it correctly
Add a fifth style called Duration that takes a integer as input and return a duration string.
As instance, if the number displayed is 678, it displays "11 minutes 18 seconds"
Should handle case when displayed value is a string or a float.