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/handlers/delivery_replay.go

@@ -310,6 +310,7 @@ func createReplayDelivery(
 		TargetConfig: target.Config,
 		MaxRetries:   target.MaxRetries,
 		Method:       event.Method,
+		RawQuery:     event.RawQuery,
 		Headers:      event.Headers,
 		ContentType:  event.ContentType,
 		Body:         replayBody(event.Body),