Add custom worker name for each rig in config

[nicoschtein]

I think it may come in handy to be able to set an option custom worker name (suffix) for each rig on setup. When we add a new Rig, one more field should be added with: Worker Name: [_____]

This way we can set better more descriptive rig names and keep workers short and simple.

[prdatur]

Will add this, this make the "rig based" pool feature more readable.

[prdatur]

implemented