Remove pad_shape in ImageInfo

[sungchul2]

Summary

This PR includes:

• Remove pad_shape in ImageInfo
  • Enable instance segmentation data pipeline #3435 (comment)
  • This issue can occur when Pad is followed by a transformation that changes img_shape like RTMDet.
    

    training_extensions/src/otx/recipe/instance_segmentation/rtmdet_inst_tiny_tv.yaml

    Lines 75 to 94 in 46ca407

    	- class_path: otx.core.data.transform_libs.torchvision.Pad
    	init_args:
    	pad_to_square: true
    	pad_val: 114
    	transform_mask: true
    	- class_path: otx.core.data.transform_libs.torchvision.CachedMixUp
    	init_args:
    	img_scale:
    	- 640
    	- 640
    	ratio_range:
    	- 1.0
    	- 1.0
    	max_cached_images: 10
    	random_pop: false
    	pad_val:
    	- 114
    	- 114
    	- 114
    	prob: 0.5

  • Some pad_shape assigned in mmx DataSample remain because it is re-initialized in DataPreprocessor
• Update stack_batch for detection

How to test

Checklist

• I have added unit tests to cover my changes.​
• I have added integration tests to cover my changes.​
• I have ran e2e tests and there is no issues.
• I have added the description of my changes into CHANGELOG in my target branch (e.g., CHANGELOG in develop).​
• I have updated the documentation in my target branch accordingly (e.g., documentation in develop).
• I have linked related issues.

License

• I submit my code changes under the same Apache License that covers the project.
  Feel free to contact the maintainers if that's a concern.
• I have updated the license header for each file (see an example below).

# Copyright (C) 2024 Intel Corporation
# SPDX-License-Identifier: Apache-2.0

[vinnamkim]

What's the reason that this should be removed?