New component: Tag

[mrosvik]

Related information and research findings:

• Tag in Entur design system
• Tag in Aksel design system
• Tag in Carbon
• Tag in Gov UK design system
• Tag in U.S Gov design system

Tag specification

• Should come in three sizes: small, medium, large.
• Should come in two variations: outline and filled.
• Should come in different colors:
  • Status: Neutral, info, warning, success, danger
  • Brand, Primary, Secondary, Tertiary. The brand color should change based on your activated theme.
• Should not be interactive.

### Tasks
- [ ] https://github.com/digdir/designsystem/issues/404
- [ ] https://github.com/digdir/designsystem/issues/490
- [ ] https://github.com/digdir/designsystem/issues/492
- [ ] https://github.com/digdir/designsystem/issues/648

[mrosvik]

The Tag component is ready for use: https://storybook.designsystemet.no/?path=/docs/felles-tag--docs