[#479] cmd/neofs-node: Add eigen trust block timer

Eigen trust block timer ticks to start new round of
eigen trust calculations. Every epoch this timer
recalculates duration and starts again.

Signed-off-by: Alex Vanin <alexey@nspcc.ru>

cmd/neofs-node/main.go

@@ -63,6 +63,7 @@ func bootUp(c *cfg) {
 	serveGRPC(c)
 	bootstrapNode(c)
 	startWorkers(c)
+	startBlockTimers(c)
 	serveMetrics(c)
 }