Print out the goroutine id (#3433)

The TXT logger prints out the actual go routine ID

This feature depends on 'loggoroutine' build tag

```go build -tags loggoroutine```

formatter/hook/keys.go

@@ -0,0 +1,6 @@
+package hook
+
+const (
+	EntryKeySource      = "source"
+	EntryKeyGoroutineID = "goroutine_id"
+)