Allow parameters of rendering macro developed in Java to be ordered

Rendering macro develop in a wiki page has ordered parameters (except that this was broken when migrating the feature to CK, see CKEDITOR-181), so it would be fair to provide the equivalent feature for Java macros. Maybe we can use an annotation in order to provides a key for sorting the parameters.

With the introduction of the "more..." button that collapse most of the parameters, this improvement is now a must have, since displaying parameters based on their label make the order vary with the language, something the user cannot get used to when they work with multiple languages. Moreover, the alphabetical order produce very weird presentation of parameters, so very useless parameter with usually a sensible default might come before more useful ones.

Moreover, until XWIKI-13282 is solved, you are in a real dilemma. Either you have to sacrifice ordering to get typing or the opposite. This is a really annoying situation.