api extension: export/import product

[dmutti]

to export, build a zip file with a hierarchical structure of the product, with file semantics.
something like

• product1
  • product-metadata.json
    • users, description, ...
  • component2/
    • component-metadata.json
      • description, ...
    • property1/
      • property-{ruleName}-metada.json
      • property-{ruleName}.value