Since we already required Swift 5.5 for Concurrency (Xcode 13), it's natural to update the demo app to reflect latest SwiftUI changes, which makes the code neater and more expressive.
- Lambda examples use async/await
- SwiftUI example uses async/await
- Handlers are marked with `@main`
- Executables are defined as `.executableTarget`
- Examples require Swift 5.5
motivation: clearer examples as we prepare to open source
changes:
* rename debugging example to make the name more accurate
* add more information in the local debugging example
* add a Shared module to show how to share code between client and server
* make example more useful - use JSON for registration like flow
* add docker-compose task to test examples
Co-authored-by: Yim Lee <yim_lee@apple.com>