fix: downgrade react-scripts to 4.0.3 (5.0.1 had issues)

[bodom0015]

Problem

Temporary fix for #18

SwaggerUI page is broken, missing the Buffer polyfill

Approach

• Downgrade react-scripts to 4.0.3 to bring back this polyfill
• Note: webpack is not customizable without ejecting webpack config

How to Test

1. Checkout and run this branch locally
2. Navigate to http://localhost:3000/swagger
   • Page should load
   • You should no longer see the Buffer is not defined error in the console