PXBF-1934-client-router-tests: Add Navigation Tests for Life Events Workflow

[nehemiah-abuga]

PR Summary

This pull request introduces automated navigation tests for the Life Events workflow. The tests ensure that each component in the flow is rendered correctly based on user interactions and URL paths.
Key Updates

• Intro Component: Renders at /death/ route.
• LifeEventSection Component: Renders at /death/about-you.
• VerifySelectionsView Component: Renders at /death/verify-selections via navigation.
• ResultsView Component:
  • Eligible items rendered at /death/results.
  • Not-eligible items rendered at /death/results/not-eligible.
• Full Back Navigation: Verifies navigation back to /death/ via browser back button.
• Query Parameter Redirection: Confirms redirection to /results when valid query parameters are present.

Related Github Issue

• Fixes #(issue)

Detailed Testing steps

• pull changes locally
• cd benefit finder
• npm run dev:storybook
• cy:run:e2e and verify all test pass