Fix serializating the random number generator for the CPO Bingham particle property.

[bangerth]

Describe what you did in this PR and why you did it.

This addresses one of the other places where we have a random number generator in plugins. This class actually serializes it, but as with the other places we had, this does not lead to reproducible results because (i) we really only save the state from process, but (ii) restore all processes from the saved state from process 0. The scheme used here ensures reproducible restarts.

Part of #6744.

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[bangerth]

Some of the test outputs change by noticeable amounts. I lack the understanding of these models to say whether that's reasonable.

@MFraters I think you wrote this class originally. Can you take a look?