apt.txt does not contains the gz-sim-yarp-plugins dependencies

[Nicogene]

I noticed that install_apt_dependencies.sh does not install the dependencies for installing gz-sim-yarp-plugin, this is because apt.txt does not contains the gz-sim-yarp-plugins dependencies.

I don't know if this is intentional (cc @traversaro @xela-95), I would add them since that script is very handy.

[traversaro]

The problem is that historically that script installed packages provided in the official Ubuntu repos. No official Ubuntu repo packages gz-sim, at least as far as I know.