Move keras-hub bounding box ops to keras main repository

[sineeli]

As of now we have temporary operations of bounding boxes in keras-hub itself. Once new release is done all these ops will be available in keras-main repository itself.

Once done we will replace all this ops with keras ops itself.

Use: https://github.com/keras-team/keras/tree/master/keras/src/layers/preprocessing/image_preprocessing/bounding_boxes
Remove: https://github.com/keras-team/keras-hub/tree/master/keras_hub/src/bounding_box