CREO2URDF – Add parameter for disable the mesh generation

[Nicogene]

Task description

The meshes generated via creo2urdf are usually not very nice, since they are created starting from the shrinkwrap.
In some cases, for having more appealing meshes, an external/manual process of mesh generation is needed:

• Add the nice meshes for ergocub V1/V1_1/V1_2 ergocub-software#266

For this reason, a flag would be useful for disabling the mesh generation (false by default).

Definition of done

The flag has been added

cc @traversaro @mfussi66