Add filtering and improves 3rd form view

_It is now possible to filter the lists of players by clicking on the columns in the header.
_the 3rd form view now uses the objets to update the age divisions and rounds played if you switch from Single Elimination mode to Swiss mode and viceversa.

TODO:
_Optional: filtering by birthdate
_Required: manage dates using Date objects
_Required: continue the 3rd form view improvements for the other radios.