Rely on lerobot robot type and teleoperator plugin architecture

[francocipollone]

Summary

By doing so we can register:

• lekiwi_mujoco_robot_type
• lekiwi_keyboard_teleoperator

And use directly both robot type and teleoperator along with all the already provided CLI.

[francocipollone]

draft at: https://github.com/Ekumen-OS/lekiwi/tree/francocipollone/lekiwi_mujoco_robot_type