Move CardGroup into shared components dir

[martha]

Description

Summary of changes:

• Move the generic CardGroup component, currently only used in the Admin Form UI, to the common components directory so it can be used in other places, such as the Admin CE Match Rule UI.
  • Extracted as a separate PR from Add Admin UI for managing global CE Match Rules #1488, because that diff is getting unmanageably large!
• Add aria text on the X button to delete a RemovableCard, resolving an axe warning

Depends on hmis-warehouse PR: n/a

How to test: No functional changes. Confirm that usages of removable cards still work correctly, such as: new Form Rule dialog; form item editor widgets such as EnableWhen, Autofill, etc.

Type of change

Code clean-up

Checklist before requesting review

• I have performed a self-review of my code
• I have run the code that is being changed under ideal conditions, and it doesn't fail
• I have used Axe DevTools to scan for accessibility issues (or not applicable)
• My code includes comments and/or descriptive variable names to help other engineers understand the intent (or not applicable)
• I have updated the documentation (or not applicable)
• If it's not obvious how to test this change, I have provided testing instructions in this PR or the related issue