Scale root transform position

[sloganking]

Is your feature request related to a problem? Please describe.

Animations move their overall position in 3d space by moving their root transform's position. Bvh file skeletons have transforms that move relative to their size, but skeleton sizes may vary between files and the proportions of a bvh skeleton may be different from the default deepMimic humanoid skeleton.

Describe the solution you'd like

the positions of the root transform in .bvh animations should be scaled to match the dimensions and proportions of the deepMimic humanoid.