Payload interaction

[slim71]

Important: the actual payload linkage and such is not in focus for this project.

Without going into too much details, automate the connection and disconnection of a payload with the fleet.

• Create or download some payload models
• Describe the supposed architecture
• Design a simple solution

[slim71]

For now only an example of cargo is present: box with handles.

The cargo will be left in a predefined position in the environment and the fleet will have to move above it before starting the actual interaction with it.

[slim71]

As of commit f529133, since the gravity tag is not viable in the present version of Gazebo, the static one is used. See gazebosim/gz-sim#504