feat: expose card component

[SpyZzey]

Description

This pr exposes our card component externally.
Introduces the public ItemCard component in our public API, which exposes the previously internal Card component.
The internal Card is removed and replaced by ItemCard, including instances in the Cards component.

• Adds public ItemCard component
• Migrates Cards component to use InternalItemCard instead of Card,
• Adds test utils (ItemCardWrapper), unit tests, and dev pages for visual regression tests,

Related links, issue #, if available: hiEUAPCbkCZS

How has this been tested?

• Manual tests,
• Unit tests,
• Screenshot tests

Review checklist

The following items are to be evaluated by the author(s) and the reviewer(s).

Correctness

• Changes include appropriate documentation updates.
• Changes are backward-compatible if not indicated, see CONTRIBUTING.md.
• Changes do not include unsupported browser features, see CONTRIBUTING.md.
• Changes were manually tested for accessibility, see accessibility guidelines.

Security

• If the code handles URLs: all URLs are validated through the checkSafeUrl function.

Testing

• Changes are covered with new/existing unit tests?
• Changes are covered with new/existing integration tests?

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.45%. Comparing base (c8acad4) to head (2d8d088).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4315   +/-   ##
=======================================
  Coverage   97.44%   97.45%           
=======================================
  Files         906      909    +3     
  Lines       26561    26632   +71     
  Branches     9582     9613   +31     
=======================================
+ Hits        25882    25953   +71     
  Misses        673      673           
  Partials        6        6           

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[jperals]

Until now, the cards in Classic were inheriting the shadow style from the container (see lines 39 to 41 in the removed file src/internal/components/card/styles.scss):

  &:not(.refresh)::after {
    box-shadow: awsui.$shadow-container;
  }

So I think to keep backwards compatibility this should be {shadowContainer}.