fix(vitest-accessibility-checker): export eRuleLevel and eAssertResult

[samueldmeyer]

Summary

• New or modified checker rule(s)
• New or modified help files
• Simulator updates
• Extension UI changes
• Automated tool changes
• Other (Provide information)

Currently, the TypeScript definitions for vitest-accessibility-checker options for accessibilityCheckerPlugin require the use of enums that are not exported for configuration. This change exports those enums.

This PR is related to the following issue(s):

• Fixes [BUG]: vitest-accessibility-checker exports eRuleLevel as a type so it cannot be used as an enum #2605

Testing reference:

• Manually checked that the imports work from both an internal project and a public example: https://github.com/samueldmeyer/vitest-accessibility-checker-example

I have conducted the following for this PR:

• I validated this fix in my local env and provided testing information above
• I understand that the title of this PR will be used for the next release notes.
• I added I agree to the DCO at https://developercertificate.org/ for this contribution. as a comment after creating the pull request.

Assets to aide review attached

• Links to design artifacts
• Links to video walkthrough of user experience
• Other

Definition of Done

• Peer review complete
• Secondary review complete
• Staging deployment verified

[samueldmeyer]

I agree to the DCO at https://developercertificate.org/ for this contribution.