Add more info to inheritance chain

[arash77]

This PR adds a same_user flag to dataset inheritance metadata to help detect whether copied datasets come from the same user. The goal is to improve plagiarism detection while avoiding false positives and without exposing user IDs. I’m open to feedback on whether this approach is acceptable or if exposing user_id would be preferred for flexibility.
This is needed because existing endpoints don’t reliably provide user info for inherited datasets, and accessing user IDs via history is only possible if the history is public or shared, which is often not the case.
This way, if the user copied a dataset, we should see somewhere from this endpoint that it is not from the user, for example:

[
  {
    "id": "3f5830403180d620",
    "name": "test",
    "dep": "Copy of 'test'",
    "same_user": true
  },
  {
    "id": "ebfb8f50c6abde6d",
    "name": "test",
    "dep": "test",
    "same_user": false
  }
]

How to test the changes?

(Select all options that apply)

• I've included appropriate automated tests.
• This is a refactoring of components with existing test coverage.
• Instructions for manual testing are as follows:
  1. [add testing steps and prerequisites here if you didn't write automated tests covering all your changes]

License

• I agree to license these and all my past contributions to the core galaxy codebase under the MIT license.

[jmchilton]

Not sold on the end goal exactly but this particular implementation and augmentation to the API seems perfectly fine to me.

[mvdbeek]

This is so awkward, I don't think this should be part of the API

It's part of an API that is already terribly awkward, so I guess it doesn't make things worse.

[arash77]

Yeah, it does look awkward to me too, but honestly I’m not sure what the ideal structure should be either.

[mvdbeek]

user_id would be preferred for flexibility.

I think I would prefer that