Improve data validation

[l0drex]

• [ ] Check uploaded file for gedcomx compatibilty, notably if all required attributes are there. Everything else should already be done by gedcomx-js.
• [x] Use the id of top level data types and add one if its not present, since we use that for urls.
• [ ] Add data that can be added automatically, mark them as extracted:
  • [ ] generations
  • [ ] events
  • [ ] facts that are shared between relationships and persons