Store and show an event's query string, and pass it on to an HTTP target when set (closes #312)

The receiver dropped the query string of every request it received, so a sender's URL parameters were silently lost. Each event now keeps it, as sent, in a new `raw_query` column of the per-webhook `events` table; a resubmitted copy carries its original's. The event log and the event's page show it in the shared request block, the event log leaving out one over 32 KiB with a link, as for headers. The archive and log targets carry it. HTTP targets gain "Pass the query string on to this target", off by default: on, deliveries, replays and resubmits append it to the target URL, joined with `&` to one already there. The access log still hides it.

Model: opus-5-5

internal/delivery/target_config_view.go

@@ -171,6 +171,13 @@ func httpConfigFields(t *database.Target) []ConfigField {
 		})
 	}
 
+	if cfg.ForwardQuery {
+		fields = append(fields, ConfigField{
+			Label: "Query string",
+			Value: "passed on to this target",
+		})
+	}
+
 	fields = append(fields, maxRetriesField(t))
 
 	return fields