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

The receiver keeps the query string of the request it received on the event, 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 with the request, the event log leaving out one over 32 KiB as it does request headers. The archive and log targets carry it. An HTTP target gets a `forwardQuery` setting, off by default, on both target forms and in the target list: on, each delivery, replays and resubmits included, appends the query string to the target URL, joined with `&` to one it already has.

Model: opus-5-5

internal/database/model_event.go

@@ -30,8 +30,10 @@ type Event struct {
 	WebhookID    string `gorm:"type:uuid;not null"                                           json:"webhookId"`
 	EntrypointID string `gorm:"type:uuid;not null;index:idx_events_entrypoint_id,priority:1" json:"entrypointId"`
 
-	// Request data
+	// Request data. RawQuery is the receiving request's query string
+	// as sent, without the leading "?".
 	Method      string `gorm:"not null"    json:"method"`
+	RawQuery    string `gorm:"type:text"   json:"rawQuery"`
 	Headers     string `gorm:"type:text"   json:"headers"` // JSON
 	Body        string `gorm:"type:text"   json:"body"`
 	ContentType string `json:"contentType"`