[structure view] integrate code generation capability of jmolecules cli

jMolecules got a new cli component that helps you to generate code (e.g. for a new aggregate root). We should integrate this capability directly into the structure view to make it easy for users to use this.

Some details:

• re-use the code generation implementation of jMolecules
• embed the implementation inside of the language server
• implement the necessary API to provide the information directly from inside of the language server
• add action items to the json structure that is used to transfer the structure view information to the client
• enable actions on the UIs

The underlying idea is that the UI is relatively lightweight here, it just displays actions on the project node, asks the user for input, and tells the language server to execute that generate action on the language server side.