Move datastructures in GlobalStateAccessor to Cython

[pcmoritz]

Why are these changes needed?

More progress along the lines of #33769 to remove Python gRPC from Ray Core.

Related issue number

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[rickyyx]

Curious what's the reason behind this change?

[pcmoritz]

It's a backport from another branch -- I'm basically uninstalling grpcio, calling ray.init(), seeing what breaks and fixing it. I'm also doing it in such a way that allows us to remove the Python protobuf package going forward (in this case it would have also been possible to reorder some files / imports, but better to do it in such a way that makes it easier to remove Python protobuf going forward).