RedShift cross-service examples using universal front-end

[brmur]

• [x] #3260
• [x] #3293
• [x] Create prototype REST backend for our React app in Java.
• [ ] .NET backend for RedShift cross-service example
• [ ] Kotlin backend for RedShift cross-service example
• [ ] Python backend for RedShift cross-service example
• [ ] PHP backend for RedShift cross-service example
• [ ] Javascript backend for RedShift cross-service example
• [ ] Go backend for RedShift cross-service example
• [ ] C++ backend for RedShift cross-service example
• [ ] Rust backend for RedShift cross-service example
• [ ] Ruby backend for RedShift cross-service example