Fix bug that creates an empty output image

[pataxis]

Describe your changes

138 reported that the cropped images saved are black. The issue is that the pre-processing was not applied to the high-resolution stream. On the way, more bugs were fixed.

object-detector:

• Pre-processing of the high resolution frame is added again to fix 138
• Fixed issue when calculating crop size of the HD image that was causing crops to be slightly off

object-detector-cv25:

• All issues found in the other object-detection example are applied also on the CV25 version
• Fixed padding function, now it copies all the channels.
• Creating an extra tensor to hold the low resolution image before padding.
• Increased the resolution of the HD image to 1280x720 from 640x360. It was previously lowered from 1920x1080 because not all the CV25 products were supporting 1080p, but it should be the maximum resolution supported by all CV25 devices.

Also, some refactoring of the variable was done to give some sense to their names.

Issue ticket number and link

• Fixes #138
• Fixes #141