Support base classes as source class for SystemEvents

Originally created on [https://issues.apache.org/jira/browse/MYFACES-3185](https://issues.apache.org/jira/browse/MYFACES-3185) by Carsten Dimmek:

Registering a system event listener in the faces-config need a concrete class like HtmlInputText. If you wan't to register a listener for let's say all UIInputs you need to explicit configure all subclasses.
```

view.RequiredValidationListener
javax.faces.event.PostValidateEvent
javax.faces.component.html.HtmlInputText

view.RequiredValidationListener
javax.faces.event.PostValidateEvent
javax.faces.component.html.HtmlInputSecret

```
etc.

Supporting base classes would be great:
```

view.RequiredValidationListener
javax.faces.event.PostValidateEvent
javax.faces.component.UIInput

```
a fine-grained configuration would be still possible through SystemEventListener.isListenerForSource(Object source)

Start by tracing how faces-config processes the source-class in system-event-listener entries and review SystemEventListener.isListenerForSource(Object source). The issue names no files or tests. Done means a base class such as UIInput can cover its subclasses while listener-level source filtering remains possible.

Written by the indexing model from the issue text.