Fix SC.TextFieldView to insert a new line when the enter key is press on a text area

A fix were already there for the SC.InlineTextFieldView class so I copy it into the TextFieldView class. I've updated the SC.InlineTextFieldView class so that it now call the super class in the case where it is a text area.

I've also removed some useless code in the SC.InlineTextFieldView class:
- A fix in the insertNewline method which is not needed anymore
- The method fieldValueDidChange which only call the super class