[Feature] Add tokens for Snackbar and Alert components

[jessicawoodin]

Closes #331

Description of Change

Added 10 tokens to semantic-light

• vads-color-foreground-inverse-on-light
• vads-color-surface-inverse-on-light
• vads-color-feedback-border-info-on-light
• vads-color-feedback-border-success-on-light
• vads-color-feedback-border-warning-on-light
• vads-color-feedback-border-error-on-light
• vads-color-feedback-surface-info-on-light
• vads-color-feedback-surface-success-on-light
• vads-color-feedback-surface-warning-on-light
• vads-color-feedback-surface-error-on-light

Added 5 tokens to semantic-dark

• vads-color-foreground-inverse-on-dark
• vads-color-surface-inverse-on-dark
• vads-color-feedback-border-info-on-dark
• vads-color-feedback-border-success-on-dark
• vads-color-feedback-border-error-on-dark

Testing Packages

N/A

Screenshots/Video

N/A

PR Checklist

Code reviewer validation:

• General
  • [x] PR is linked to ticket(s)
  • [x] PR has changelog label applied if it's to be included in the changelog
  • [x] Acceptance criteria:
    • All satisfied or
    • Documented reason for not being performed or
    • Split to separate ticket and ticket is linked by relevant AC(s)
  • [x] Above PR sections adequately filled out
  • [x] If any breaking changes, in accordance with the pre-1.0.0 versioning guidelines: a CU ticket has been created for the VA Mobile App detailing necessary adjustments with the package version that will be published by this ticket
• Code
  • [x] Tests are included if appropriate (or split to separate ticket)
  • [x] New functions have proper TSDoc annotations

Publish

If changes warrant a new version per the versioning guidelines and the PR is approved and ready to merge:

• [x] Merge main into branch
• [x] Merge branch to main
• [x] Verify that Check Component Integrations workflow ran successfully
• [x] Publish new version after merging

[TimRoe]

What is the reason for the mismatch in tokens added between light and dark mode?