Cherry-pick deterministic-indicesSyncer

Lisa Julia Nebelrequested to merge
lisa_julia.nebel/dune-istl:cherry-pick/deterministic-indicesSyncer into releases/opm

@markus.blatt: I've cherry-picked the commits from !553 (merged) and moved the entry in the CHANGELOG.md to 2.9. Can you have a look and then also merge this one !554 (closed)?

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