Customizations to the build process of JSS React Native apps

A custom babel preset that encapsulates other babel plugins - this allows for swapping module dependencies at build-time based on the application mode used during development. Read more about available application modes for JSS React Native applications.

The addition of the --reset-cache argument to the start script provided by the Metro bundler - this argument instructs the bundler to ignore its dependency cache during the build process, ensuring that the babel customizations mentioned previously are invoked.