[Issue #1968]: Add withFeatureFlag HOC

[rylew1]

Summary

Fixes #1968

Time to review: 2 min

Changes proposed

• add withFeatureFlag higher order component

Context for reviewers

• Able to wrap any server component page with this React HOC - helps keep the server page component thin

https://github.com/HHS/simpler-grants-gov/assets/93001277/21c17ff9-a2de-4d75-bd09-7f9fc7456211

[github-actions[bot]]

Coverage report for ./frontend

St.:grey_question:	Category	Percentage	Covered / Total
🟢	Statements	84.11%	868/1032
🟡	Branches	65.01%	223/343
🟡	Functions	75.58%	164/217
🟢	Lines	84.15%	807/959

Test suite run success

164 tests passing in 56 suites.

Report generated by 🧪jest coverage report action from 24e2811ecd0586c397464473d65b1fee7f5f744f