synchronization and single-trial mode

New automatic post-synchronization tool:

• Tried cross-corr for sum of keypoint 2D speeds
• Tried cross-corr for sum of keypoint vertical speeds
• Tried cross-corr for sum of keypoint vertical positions
• Tried idem with sum of all keypoints vs selected keypoints
• Tried idem with sum of weighted selected points (L190 synchronize_cams_draft deleted)
• Tried idem with only right/left side
• Tried idem with frames around a specified time
• Tried cross-corr for each kpt, select top N highest correlations, take median offset (L244 synchronize_cams_draft deleted)
• Tried cross-corr for each kpt, weighted by correlation
• Tried threshold on vmax thresh
• Tried correlation threshold
  -> Best results (accuracy, simplicity, speed): sum of vertical speeds.
  Default: all keypoints, all frames. User can also choose specific keypoints at specific instants.

Single-trial mode:

• Batch mode still available
• Also works with a simpler folder structure, filled with a Config.toml file, a calibration folder, and a pose folder

What's Changed

• Process non filtered data if there is no data filtered in folder by @ANaaim in #86
• objp should not be objp_not_used by @ANaaim in #91
• Synchronization & single-trial mode by @davidpagnon in #94

Full Changelog: v0.7.2...v0.8.0