* feat: unitree go2 sim and real support
* feat: remove the `use_history` field, add `observations_history` to support history observations, and adjust the related logic to handle the case of empty history observations
* feat: fix coordinate bug in ang_vel
* fix: simplified handling of historical observation parameters, ensuring initialization of the observation history buffer in non-empty cases.
---------
Co-authored-by: fan-ziqi <fanziqi614@gmail.com>
JiJie Huang