Add icon to the footer toolbar

I am trying to add an icon using the default 'green', 'orange', and 'red' icons.

I assumed the type would be of 'Action' where I could register something near the editor cursor location / memory status but after going though all of the action groups I could not find what I want. Another spot that might work is the 'save', 'run', 'debug' toolbar but again I could not find that either.

If this is part of a Project component is there an example I can use to use?

Thanks in advance.