formatLength() with configured units

[DieuAnh]

Currently, there's no ability to choose different units (only in km/m) for two methods formatLength(), formatArea() in MeasureUtil. It would be great if you could add an option to handle different units (cm/mm/...).

[marcjansen]

Can you come up with a PR? That'd be much appreciated.

[weskamm]

this would be great as currently the formatArea method returns extreme low values when the input geometry is not in a metric projection. I think it should default to meters in that case and a transformation would be needed therefor