Add ASN to logtail, collector, aggregator, frontend and CLI

cmd/frontend/frontend_test.go

@@ -220,8 +220,17 @@ func TestDrillURL(t *testing.T) {
 	if !strings.Contains(u, "f_status=429") {
 		t.Errorf("drill from status: missing f_status in %q", u)
 	}
+	if !strings.Contains(u, "by=asn") {
+		t.Errorf("drill from status: expected next by=asn in %q", u)
+	}
+
+	p.GroupByS = "asn"
+	u = p.drillURL("12345")
+	if !strings.Contains(u, "f_asn=12345") {
+		t.Errorf("drill from asn: missing f_asn in %q", u)
+	}
 	if !strings.Contains(u, "by=website") {
-		t.Errorf("drill from status: expected cycle back to by=website in %q", u)
+		t.Errorf("drill from asn: expected cycle back to by=website in %q", u)
 	}
 }