Expose modules of the lib folder

[vincentfretin]

Transform the package to "type": "module", and expose with the "exports" field the modules of the lib folder to be consumed as a npm dependency. This will allow to reuse all the non ui code with an alternate ui. This will also allow to keep maintaining this code in the long term because it will be used for other use cases.

I'll probably implement the undo feature #21 at one point in one of my project with my own ui, but the logic will be ui agnostic so I can contribute it back if you agree to such a change @dmarcos otherwise it will just stay in my private repo.

Depends on:

• Fix some UI issues #638
• Some code cleanup #639
• Update all the dependencies, mainly webpack and react #641
• printEntity function in lib/entity.js introduces a React dependency that is not wanted if you write an alternate ui with solidjs for example, this needs to be moved to a proper component in the components folder.

[vincentfretin]

I'll do that in a community fork or just have a copy of all files in my project for now. Any new features will be implemented in the community fork as well.