Upgrade to Storybook 7.0

[MrBartusek]

This PR bumps storybook 6 to 7. Storybook is frontend workshop that we use for library development. Changes:

• Bump storybook and all addons to 7.x
• Run storybook auto migrations (add babel, eslint plugin)
• Migrate from abandoned @storybook/addon-postcs to @storybook/addon-styling
• Migrate to Component Story Format 3