Restructure build

[sdirix]

Motivation

• Clean and slim build for an eventual release

Solution

• Setup a clean build of the lib package (Rollup)
  • ESM and CJS
• Remove special library source consumption (rescripts) in released app
  • Remove all src imports (@jsonforms/editor/src)
  • Remove src import in rescripts
• Evaluate removing rescripts completely -> How to configure CRA to include Monaco Editor
• Setup a convenient development environment: 1-script solution to start coding on app and library (e.g. npm run dev).