[WIP] Add state in segments id calculation
# What does this PR do?

At the moment, when segments are calculated it's calculated on an image-per-image basis. This means  when predicting with certain models e.g. DETR, the segment id that each class corresponds can be different across each image in a batch and across batches. 

This PR adds a private attribute to the image processor class to store the class: to segment_id mapping as state. 

/!\ There is a possible breaking change, as `compute_segments` now returns 3 rather than two objects. 

Fixes #23461

## Before submitting
- [ ] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
- [x] Did you read the [contributor guideline](https://github.com/huggingface/transformers/blob/main/CONTRIBUTING.md#start-contributing-pull-requests),
      Pull Request section?
- [ ] Was this discussed/approved via a Github issue or the [forum](https://discuss.huggingface.co/)? Please add a link
      to it if that's the case.
- [ ] Did you make sure to update the documentation with your changes? Here are the
      [documentation guidelines](https://github.com/huggingface/transformers/tree/main/docs), and
      [here are tips on formatting docstrings](https://github.com/huggingface/transformers/tree/main/docs#writing-source-documentation).
- [ ] Did you write any new necessary tests?

_The documentation is not available anymore as the PR was closed or merged._