Update tutorials and examples to work, now that GLWindow.jl has been archived.

[ajahraus]

Many of the tutorials and examples no longer work at all, because they depend on GLWindow.jl , but that package has been archived and cannot be added from the REPL in Pkg mode. These tutorials and examples should be updated so that they no longer need that package.

[sairus7]

I've tried to run tutorials too, most of them not working.