Animator introspection functionnality

[hai-vr]

Many of the functionality in AAC is bound to the active animator sublayer created within it, but some may be reaching out to other layers or outside the animator:

• Getting the layer index for sub-layer blending behaviours
• Reordering layers
• Removing unused parameters
• Creating an avatar mask for the base Gesture layer
• Creating an avatar mask for FX sub-layers

Some of these operations require introspecting the entire animator's state machine and animations, which can be expensive depending on the size of the animator.

There may be a need to expose a dedicated API in AAC that is specialized in animator introspection.