Allow deriveColumnDescriptions to use first n rows for deriving

[puehringer]

It would be great if the deriveColumns functions of the builder would not just use the first = data[0] row, but n rows. This could be passed as IDeriveOptions for example, with n = 1 staying the default. I think we can keep it very simple, i.e. by letting deriveType return a flag if the returned column is the "default"/not inferred one, and we keep doing this until we reach n iterations or find a non-default column.

User story

Generally, this is needed when you have columns with missing values, i.e. [null, 'https://...', ...]. This will cause the default to be triggered (i.e. returning a string column).