OTX Data Clean Up

[kprokofi]

After Experimental datumaro implementation (#4920) there is some refactoring is needed.

1. Improve checks and edge cases handling like HWC -> CHW transformations
2. Remove OTX Data Item since we are using OTXSample from Datumaro, rename all docstrings and typing. Remove torch entity. Move / Combine OTXDataBatch / Predict with new OTXSample
3. Remove OTX Img Info, since we can use now Datumaro Img Info
4. Remove Polygons from the whole pipeline, since we don't use them anymore
5. Fix unit tests (migrate from OTXDataItem to OTXSample, remove polygons, add new tests for OTXSample, etc.)
6. Update/remove legacy datumaro format when new one will be fully supported on the Datumaro side