Add support for 10kg and 12kg variants of GoFa robots (abb_crb15000_support)

[gonzalocasas]

There are two more models on the GoFa product line for 10kg and 12kg payloads. It would be great to add support for them to this package. Is there a source from which we could get a hold of the URDF and meshes of those models? If so, I can prepare the PR to add it to this repo.