Rename packages with prefix xcub

[martinaxgloria]

This PR includes several changes in the project to address:

• Suggestions: use more specific package names? #28

Configuration file renaming:

• Renamed all the packages with the xcub_ prefix and the related references in the project

Documentation updates:

• Updated package names and paths in the README.md file to reflect the new naming conventions

Changes tested in simulations.

[traversaro]

Thanks! Minor nitpick on the xcub_grasp and xcub_robot packages that are still pretty generic and do not describe a lot what the package is actually doing. Could it make sense to call them xcub_moveit_grasp and xcub_moveit_robot ?

Consider that the package name also induces the CMake package name used in find_package, and having the name find_package(xcub_grasp) or find_package(xcub_robot) for something that is not extremely generic may be confusing.

[martinaxgloria]

Hi @traversaro, you're right. I renamed the last two packages as you suggested here d40c714