Add support for H1-2

[MaggieK410]

Hi,

thank you fir this great repo. I found that the message type unitree_go_msg_dds__LowState_ is incompatible with H1-2, because the array is of fixed size 20. While this is true for H1, H1-2 has 27 joints and this message type cannot be used anymore. Is there another message type that is supposed to be used for H1-2?

Thank you in advance!