Name log fields, metrics and the Core Rule Set package for what they are (closes #192)

Log field, metric, action and event names now say what they count
and, for timings, the unit. Package internal/waf is internal/coreruleset.

Model: opus-5-5

internal/discriminator/bans_test.go

@@ -415,7 +415,7 @@ func startWithClock(
 
 // sender sends requests to rproxy one after another, each on a connection of its
 // own, and checks each one's answer and log line. discriminatorAddr is where
-// discriminator's own endpoints are, which adminRequest asks. Every request
+// discriminator's own endpoints are, which ownEndpointRequest asks. Every request
 // discriminator gets must come through the sender, since the log lines are
 // matched to them in order.
 type sender struct {