Klaus 280 discard pose data when convex hull is larger than expected mouse size

[SkepticRaven]

Changes:

• Adds new CLI util for unmarking mice that appear too big.
  • Calculates bounding boxes for keypoints and unmarks assigned identity and confidence values for keypoints when greater than a threshold.
  • Calculates bounding boxes for segmentation and unmarks assigned identity when greater than a threshold.
• Adds bounding box qc inspection metric
  • Note: IF the above filtering occurs, these will appear as "missing" and not "big poses"
• De-duplicates some leftover migrated functions from Alex's refactor (Repository reorganization #72)
  • Removes utils.pose completely. These functions have been migrated elsewhere.
  • Moves location of downgrade_pose_file to resolve a circular import.