add theming to ExpandableCard

[sorenoid]

Related to issue: #4518

Description:

add theming composition locals to the shared ExpandableCard composable component so that theming on behalf of one consumer of the component don't affect other consumers of the component.

Summary of changes:

• composition locals for typography, shapes, and color
• ExpandableCardTheme composable
• default tokens for use in previews

Pre-merge Checklist

• a vTest Job for this PR has been run
  • [x] link: https://runtime-kotlin.esri.com/view/vTest/job/vtest/job/toolkit/71/
• Unit and/or integration tests have been added to exercise this PR's logic, and the tests are passing:
  • [ ] Yes
  • [ ] No

[sorenoid]

merging with feedback implemented -- Kaushik is out sick will pick up any further feedback in follow on PR