Add the possibility to use the full macro parameter type class name (including package) for the parameter displayer

Currently only the class name of the macro parameter type is used to define/compute the parameter displayer path, so conflicts can happen, for example when several macros have parameter types sharing the same class name.

Macro 1 parameter type : org.xwiki.macro1.SomeType
Macro 2 parameter type : org.xwiki.macro2.SomeType

So, to avoid macro parameter displayer conflicts we should add the possibility to use the full class name including package.