Reimplemented fix in #2198 in @rjsf/utils package

[heath-freenome]

Reasons for making this change

The fix in #2198 is simple and fixes a pretty bad issue (Thanks @QingqiShi)

• The fix in fix: oneOf anyOf default value always using first option #2198 needed to be refactored into the new @rjsf/utils package
• Replicated the fix into the getDefaultFormState.ts file
• Replicated the additional tests into getDefaultFormStateTest.ts and oneOf_test.js
• All of these change are identical to what is in the original PR with the addition of mocking return values for the utils tests
• Updated the CHANGELOG.md with the note for this fix along with the notes for PR Fix package links in README files #3094

Checklist

• I'm updating documentation
  • I've checked the rendering of the Markdown text I've added
• I'm adding or updating code
  • I've added and/or updated tests. I've run npm run test:update to update snapshots, if needed.
  • I've updated docs if needed
  • I've updated the changelog with a description of the PR
• I'm adding a new feature
  • I've updated the playground with an example use of the feature

[nickgros]

LGTM, thanks @heath-freenome and @QingqiShi