Cleanup metrics (#3776)

Cleanup a variety of metric issues.
* Eliminate department of redundancy "count_total" naming.
* Use the plural of the unit when appropriate. (ex, "requests")
* Remove label names from metric names where appropriate. (ex, "rcode")
* Simplify request metrics by consolidating type label in to the base
request counter.
* Re-generate man pages.

Signed-off-by: Ben Kochie <superq@gmail.com>

Co-authored-by: Ben Kochie <superq@gmail.com>

plugin/autopath/metrics.go

@@ -10,7 +10,7 @@ var (
 	autoPathCount = prometheus.NewCounterVec(prometheus.CounterOpts{
 		Namespace: plugin.Namespace,
 		Subsystem: "autopath",
-		Name:      "success_count_total",
+		Name:      "success_total",
 		Help:      "Counter of requests that did autopath.",
 	}, []string{"server"})
 )