Control rig doesn't support differently-sized skeletal meshes

[corbin-poteet]

Describe the bug
Due to the way that CR_Mannequin_Als handles pelvis offset, differently-sized skeletal meshes aren't handled properly by our control rig, resulting in smaller skeletal meshes (like Quinn) hovering above the ground. In order to resolve this, we need to set the leg length after a skeletal mesh has been applied, but before it starts animating.

To reproduce
Steps to reproduce the behavior:

1. Use the PawnCosmeticComponent to apply the B_Quinn cosmetic to B_Hero_Mannequin_Als
2. Look at the feet in relation to the ground

Additional context
This can be worked around by applying the desired skeletal mesh as the preview asset in CR_Mannequin_Als, but this solution isn't desirable in a modular system like Lyra, as it would require different animation blueprints, control rigs, and characters for every different body type.