Add a controlled type option to the simple textbox component

[jrdh]

We have a general textbox component which provides a basic textbox. Would it be worth surfacing a type option to allow developers to create different kinds of textboxes (e.g. password, email etc)? We'd probably want to limit the options so that people don't abuse this by passing a non-textbox input type (e.g. "button") and turning the textbox into something completely different.