Metahuman animation toolset. Part 1

This is WIP of my Metahuman animation toolset. The tool is derived from the previous animation toolkit that I developed for my own human-like characters a few years back. Features shown:
- Control rig creation based on Metahuman default skeleton
- Some control panel capabilities
- Namespace-based multi-character use

Create a user-friendly rig based on the Metahuman skeleton with one click of a button.

Control FK-IK systems via viewport controls or the GUI control panel.

Select controls with GUI. Key modifiers and marquee selections are available for the best user experience.

Limbs offset controls for the final adjustments.

Reverse foot-roll controls

Secondary controls visibility

Animate multiple characters in a single scene using namespace selector