feat(utilities): update .u-list-style-* styling

[jzempel]

• BREAKING CHANGE?

Description

Matches the <ol> > <li>/<ul> > <li> styling provided by react-components.

Detail

See zendeskgarden/react-components#388.

Demo pre-published for review: https://garden.zendesk.com/css-components/utilities/list-style/

Checklist

• 👌 style updates are Garden Designer approved (add the
  designer as a reviewer)
• 🌐 component demo is up-to-date (yarn start)
• ✅ all component states are represented
  (.is-hovered, .is-focused, etc.)
• ⬅️ renders as expected with reversed (RTL) direction
• 🤘 renders as expected sans Bedrock (?bedrock=false)
• 💅 provides custom.css example for modifying the
  primary accent color
• 📝 tested in Chrome, Firefox, Safari, Edge, and IE11