A flow named for a different substance than its own

This flow's own name answers for a different substance than the one the flow sits on, so giving the flow its substance's name would delete the only visible symptom of what may be a mis-grouping: either the two substance records are one substance, or the flow is on the wrong one (#588). The flow keeps its name until a ruling in `preferred-label-decisions.json` answers the pair: `approve` says the grouping is right — the flow takes its substance's name, and the old name is published as a synonym of neither substance, because a name that answers for two is a name for none (#571). `reject` says the flow's own name stands. If the grouping itself is wrong, the answer is not a ruling here but a split, and the row waits until it has one.

substance-label-conflict