Improve Interpreter binding dialog

Currently, "interpreter binding" dialog lists available interpreter settings.
User can enable / disable them and drag to the top, to make it default. (screenshot attached)

I think we can think better UX for interpreter binding dialog by considering,

• Expose interpreter restart button for convenience
• Instead of drag and drop to make default, we can just think about radio box or something more intuitive. Maybe with ZEPPELIN-707 default interpreter can fade away