feat: Import yolo semantic segmentation labels

[pablohernandezdo]

HI!

This implements the functionality to import yolo formatted semantic segmentation labels. It generates the .xml label configuration file and the .json tasks file, just as the currently implemented object detection import.

I basically adapted the existing object detection import method on a new file to process the segmentation labels, added the corresponding subparser in the main script to extend the cli input arguments from (yolo|coco) to (yolo|yolo-seg|coco) and updated the documentation to include the new argument. I also adapted the object detection tests and added the corresponding tests for semantic segmentation.

As the label-studio contributing guide specifies, I tried to use ruff and blue for linting and coding style. Ruff raised errors on files that I didn't modify and blue also changed files that I didn't touch, so I just left them as they were and opened the PR for further guidance.

[makseq]

After careful consideration, we’ve determined that this is more of an improvement than a critical bug. Additionally, it seems to be an outdated request and hasn’t garnered much interest from the community. For these reasons, we will be closing this issue. We will continue developing the converter library as a part of Label Studio SDK.

We appreciate your understanding and encourage you to submit your feedback, questions and suggestions here:
https://github.com/HumanSignal/label-studio-sdk/issues