Add ComparisonAnnotator, xyxy_to_polygons

[LinasKo]

Description

ComparisonAnnotator enables comparing of two Detections objects, highlighting the difference. It's useful for both model-model and prediction-target comparison.

Features:

• ComparisonAnnotator itself
• ComparisonAnnotator automatically selects whether obb, mask or xyxy should be used.
• If labels are specified, text boxes with color markers will be drawn
• Only one parameter is required to modify label size - no need to think about text thickness, font, etc
• xyxy_to_polygons utils function

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

How has this change been tested, please provide a testcase or example of how you tested the change?

• Colab: https://colab.research.google.com/drive/1jyGF5cwxrbqrLs4ZFTIeBMaFUtbklqyh?usp=sharing
• TODO: Docs not yet tested

Examples in comments.

Any specific deployment considerations

None

Docs

• Docs updated? What were the changes:

[LinasKo]

[LinasKo]

Docs updated, but commented out two tabs in the preview: BoxCornersandCrop` annotators.

This is due to an issue I found - a maximum of 20 tabs is possible at the moment. #1729