[conan] Expose get_python_version if the recipe is used downstream
[conan] Expose get_python_version if the recipe is used downstream

jrl-umi3218/RBDyn,jrl-umi3218/RBDyn,gergondet/RBDyn,gergondet/RBDyn,jrl-umi3218/RBDyn,gergondet/RBDyn,gergondet/RBDyn,gergondet/RBDyn,jrl-umi3218/RBDyn