Add support for textured meshes in Gazebo

[Adam Conkey]

Right now for YCB objects we just use the STL meshes which do not have texture. The textured meshes are available for YCB objects but we have not yet tried to incorporate these into Gazebo. The main motivation is to just have nicer looking simulation environments for paper submissions or demos that utilize the simulator.

[Balakumar Sundaralingam]

This could be an msg option for passing textured meshes: https://github.com/marip8/colorized_mesh_display

I have been using this in RVIZ and they are not resource intensive