feat(styles): add component token support for Sass Migration effort

[joshblack]

This PR updates the theme mixin to include component token maps which can be generated by a get-tokens helper now available in utilities/component-tokens. This should help unblock any efforts that use component tokens in our sass module refactor.

More usage info for this approach can be found in: carbon-design-system/carbon-v11#1

Changelog

New

• New utilities for working with component tokens, specifically a helper that lets you get the tokens from a token map for a specific theme

Changed

• Update theme helper to take in a list of maps to allow component tokens to be passed in

Removed

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[tw15egan]

LGTM 👍 ✅