Serve a key's kept values so the issue tracker can carry them into its log (ADR 0307, issue 502)

mesh/state.history answers every value a bucket still keeps for a key,
oldest first, to whoever may get it, by the same watch the runtime already
uses, so no new grant is needed.

node-tools/internal/meshtest/meshtest.go

@@ -220,6 +220,17 @@ func (m *Mesh) Pending(t *testing.T, node, module string) (ackPending, notDelive
 	return uint64(info.NumAckPending), info.NumPending
 }
 
+// BucketKeeping makes a module's state afresh as Bucket does, keeping up to history values a key.
+func (m *Mesh) BucketKeeping(t *testing.T, name string, history uint8) nats.KeyValue {
+	t.Helper()
+	_ = m.js.DeleteKeyValue(name)
+	kv, err := m.js.CreateKeyValue(&nats.KeyValueConfig{Bucket: name, History: history, MaxValueSize: 256 * 1024})
+	if err != nil {
+		t.Fatal(err)
+	}
+	return kv
+}
+
 // Bucket makes a module's state afresh as the controller does from the catalogue (novox/hq ADR 0201),
 // and answers it for writing what is there before a bundle starts.
 func (m *Mesh) Bucket(t *testing.T, name string) nats.KeyValue {