[Material] Pickers

[PureWeen]

Material Contained Picker Spec

Currently all of the picker fields themselves are basically just Entry controls. For the first pass of Material we will style the text field based on Material Entry but we won't create material versions of the pop ups themselves. For example the DatePicker will still popup natively on iOS and Android.

TimePicker, DatePicker, and the Picker control will all be included with this update

The control itself will just be a Filled Textfield (#4949) using a transparent background