[topic/Go2] Add convexified mesh of body and calf for collision

robots/go2_description/collisions/base_body_convex.stl

robots/go2_description/collisions/base_fl_support_convex.stl

robots/go2_description/collisions/base_fr_support_convex.stl

robots/go2_description/collisions/base_head_convex.stl

robots/go2_description/collisions/base_neck_convex.stl

robots/go2_description/collisions/base_rl_support_convex.stl

robots/go2_description/collisions/base_rr_support_convex.stl

robots/go2_description/collisions/calf_lower_convex.stl

...s/go2_description/collisions/calf_lower_mirror_convex.stl

robots/go2_description/collisions/calf_upper_convex.stl

...s/go2_description/collisions/calf_upper_mirror_convex.stl