Upgrade Storybook to version 5.x

We are currently using Storybook 4.x in stripes-components. Version 5 has been out for a while now and we should upgrade to get access to more features and generally a better user experience.

This upgrade requires:

• Upgrading Storybook and all addons from 4.x -> 5.x
• Updating the global storybook configuration
• Updating most stories to use the updated Storybook API