Create andino_gz_demos package

[francocipollone]

Summary

• Creates andino_gz_examples package
• Move there example of using the sim with andino_slam/slam_toolbox
• Create a demo spawning many andinos
• Create a nav2 integration example.

[WilliamBaltus]

Looking forward to these!

[WilliamBaltus]

Hey Franco, if I wanted to switch to using the diff drive odometry, what would I change in its parameters? For example I change odom_topic to just "/odom." What else if you know off the top of your head? I want this to work with the slam_toolbox configuration at default (which I guess uses the andino_slam config yaml). Does andino have slack?