Desirable features to simplify migration of ami-iit lab to gz-sim

[traversaro]

Just collecting some discussion with @LoreMoretti and @GiulioRomualdi .

The two biggest "missing feature" w.r.t. Gazebo Classic + gazebo-yarp-plugins are:

• Investigate how to set the initial position of models included in world #159
• GUI Crash when resetting the simulation #206

Two nice improvements that are not present in Gazebo Classic + gazebo-yarp-plugins, but they could be useful to force users to migrate to gz-sim:

• Avoid to use modified models to deal with numerical instabilities in Gazebo and related tools icub-tech-iit/ergocub-software#276
• Ensure that enable_tags and disable_tags options can be passed in a world SDF file to the gazebo_yarp_robotinterface of an included model #163

Another issue (not tracked here) is the implementation of jet plugins for iRonCub simulation (fyi @Giulero @HosameldinMohamed @xela-95).