Add SwiftUI Button

[mpospese]

Implement a SwiftUI version of TypographyButton.

It should be named TextStyleButton and it should wrap TypographyButton using a TypographyButtonRepresentable.

See TextStyleLabel and TypographyLabelRepresentable for how to structure code and how to unit test as best as possible.

The import parts are that the button should have a height that is determined by the line height of the Typography (and whatever padding it might have).

It's OK for this to be only for single line buttons (just as TextStyleLabel is only for single line labels for now).