feat(card-group): Add Card Group component

[macandcheese]

Related Issue: #7223

Codepen preview of the new functionality: https://codepen.io/mac_and_cheese/pen/gOEyZPz?editors=1000

Summary

Adds a new Card Group component with a selectionMode capability.

• Follows selectionMode paradigm from other components with values of multiple, single, single-persist, none (default).
• Has a readOnly selectedItems property and calciteCardGroupSelect event.
• Keyboard navigation between focused Card elements with arrow keys, using Space / Enter to interact.
• Mouse user can use the visual icon affordance - it is not included in tab order and focuses the card body.

Changes to Card:

• Monitors content in default slot and conditionally applies padding when needed.
• Deprecates selectable from Card (direct replacement is a parent Card Group selectionMode: multiple)
• Deprecates title, subtitle slots and adds heading and description to align with naming convention.
• The calciteCardSelect event remains and will continue to work post-removal of selectable in a future breaking change release.
• Adds deselect translated message.
• Styling / alignment updates.

Todo:

• Update css to use the updated token refactor from 7180 to prevent merge conflicts
• Card stretch / wrap improvements

[SkyeSeitz]

Looks g2g from the design end! ✨

[jcfranco]

Confirmed low-risk as it makes minor updates to card.

[jcfranco]

we might need a "new component" checklist doc for this one.

@driskull Excellent idea! Do we have something along those lines we could use as a base? This seems familiar. 🤔❓

[driskull]

I think the conventions doc is what we got. Maybe we just add a new components section for ease of linking and finding. We can copy or link to the usage doc and stencil config parts.

[driskull]

Might be nice to beef up our conventions to talk about usage guidelines for the following as well:

• requestAnimationFrame
• componentOnReady
• forceUpdate
• readTask
• writeTask

[macandcheese]

@jcfranco made some updates to address feedback, @geospatialem I made some changes to better support JAWS / NVDA - can you give a test? Seems good on VM for a11y testing on my end.