Add play functions in stories (for testing purposes)

[panzacoder]

Acceptance Criteria/TODO:

• Test style changes with interaction (e.g. hover, active):
  -- Breadcrumbs, Buttons, Checkbox, Dropdown, Input, Link, Radio, SegmentControls, Slider, Tabs, Tags, Toggle

• Test value change with interaction:
  -- Bar: no change when passed isStatic prop
  -- Slider

Decisions/Discovery:

• No need for testing style changes related to user interactions
  -- Browser's don't have a good way to check computed values (e.g. background-color) while a pseudo-class is applied (e.g. hover)