Add membership and host to user webhook payload

Nest membership ID, role, and state into a membership sub-object
in the user webhook payload. Also emit user:updated webhook when
the membership role is changed. Add X-Probo-Webhook-Host header
to webhook HTTP calls. Skip delete webhook when membership is
not found in SCIM user deletion.

Signed-off-by: Sacha Al Himdani <sacha@getprobo.com>

pkg/probod/probod.go

@@ -612,6 +612,7 @@ func (impl *Implm) Run(
 		Interval:      time.Duration(impl.cfg.Notifications.Webhook.SenderInterval) * time.Second,
 		CacheTTL:      time.Duration(impl.cfg.Notifications.Webhook.CacheTTL) * time.Second,
 		EncryptionKey: encryptionKey,
+		Host:          baseURL.String(),
 	})
 	wg.Go(
 		func() {