Root Motion

[effs]

Fixes

• Root Motion export logic (incl. yaw-only rotations)

Adds

• Root Motion import
• Lightweight type level support for differentiating ZupLhs (wkit) and YupRhs (glTF) coordinates so that you can enforce using the correct one in the correct place plus conversions

Other

• Ton of refactoring in AnimTools and , primarily there's now a struct for passing the data around from and to encoders so that logic is not duplicated where possible.

Detes

• Root Motion export with toggle, import without toggle based on glTF data
• Root Motion is Translation and possibly Rotation, type dependent. No Scale.
• Only Root Motion or regular root joint transforms (if any) are exported, not both, not mixed
• glTF storage for RM is in root joint, as per above
• glTF extras for each anime schema v4 includes RootMotionType that tries to be clearer on intent
  • None if RM requested but there's none
  • Unknown if not requested (whether or not one exists)
  • Others if requested and found
• Previous schemas migrated with RootMotionType.Unknown
  • None uses root transforms as regular and deletes old RM
  • Unknown copies old RM from CR2W, if any, doesn't touch root joint, essentially equivalent to toggle
  • Others store indicated type and clear root joint transforms

Also Done

closes #1692

TODO separately

• Import Yaw-Only Root Motion Rotations Optimized Storage #1796
• Actually Use Type-Level Coordinate and Vector Checking #1788

[effs]

@seberoth Not sure how worthwhile it is to dig into the actual logic here but if you have the chance, I'd like your eyes on

1. The type-level stuff and the more fp-style flow over iteration, if there's anything too jarring

2. The epsilon and other normalization both in that it makes sense and whether we need it elsewhere