Remove non-generic methods from the WikiComponent interface

The WikiComponent interface allows to implement components with a generic mechanism (XWiki.ComponentClass, XWiki.ComponentMethodClass, etc). It can also be extended to allow Java components to be bound to documents. 3 methods are required by the first use case but not the second one, those methods should be moved to the implementation :

List<Class< ? >> getImplementedInterfaces();
Map<String, XDOM> getHandledMethods();
Map<String, ComponentDescriptor> getDependencies();