Add filterDrawerWhatIfFacets.feature under new folders for #7075

[Bhavna-Ramachandran]

Summary

Work for : Issue #7075

Changes proposed

• Created folder structure: /frontend/tests/e2e/search/features for adding all search-specific feature files.
• Created sub-folder structure: /frontend/tests/e2e/search/features/filterDrawer for adding all search/filterDrawer-specific feature files.
• Created draft scenarios to verify and validate what-if facets, including:
  1. Funding Instrument
  2. Eligibility
  3. Closing Date Range
• Added feature file: /frontend/tests/e2e/search/features/filterDrawer/filterDrawerWhatIfFacets.feature

Context for reviewers

• This is the first BDD feature file for the search/filterDrawer workflow.
• Reviewers should verify that all critical user flows are covered.
• The scenarios listed in the feature file will be automated using Playwright in future PRs.

Validation steps

• Confirm the feature file exists at: /frontend/tests/e2e/search/features/filterDrawer/filterDrawerWhatIfFacets.feature
• Review the Gherkin scenarios to ensure they cover all critical user flows.
• Verify the folder structure allows for future feature files to be added consistently.