feat(mdc-card): add `appearance` input

[andrewseguin]

Feature Description

MDC provides an mdc-card--outlined class that changes the card's appearance to be zero-elevation with a border. The card should have an input for users to select which appearance they want: raised | outlined

Use Case

See this documentation for details on the outline appearance: https://material.io/components/cards/web#other-variants

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