mesh-knowledge: clear a never-reviewed notice once the record moves on, key it by version and run of tries, say times locally (review of #219)

A notice left open kept telling the operator a record was proposed and not in force after it was proposed again
or accepted, and a later version's notice merged into it.

modules/mesh-knowledge/README.md

@@ -107,8 +107,9 @@ as text. `get` serves each, and any other field a record of hq wrote under `fiel
      approval. It is owed: its try count and when it is asked again (10, then 20 minutes later) are kept with the
      version in the store and said in its history, so the background work takes it up at that time, also after a
      restart of the tool runner (hq issue 497). After 3 tries the record says it was the last and its author
-     proposes it again to have it reviewed again; the operator is told once on the operator's channel, and the
-     module is unhealthy, naming it, so the mesh raises a condition.
+     proposes it again to have it reviewed again; the operator is told once on the operator's channel (keyed by
+     record and version, and cleared once the record is proposed again, accepted, withdrawn or superseded), and
+     the module is unhealthy, naming it, so the mesh raises a condition.
      An ask of the operator that cannot be made counts as a try the same way.
    - A review whose outcome the database refused to keep is held back for that record alone (10, then 20
      minutes, 3 tries, logged as given up), so it never blocks the records behind it.