VLESS Reverse Proxy: Check burstObservatory immediately after inbound adds new reverse-mux to reverse-outbound (#5752)

Fixes https://github.com/XTLS/Xray-core/issues/5750

---------

Co-authored-by: RPRX <63339210+RPRX@users.noreply.github.com>

features/extension/observatory.go

@@ -13,6 +13,11 @@ type Observatory interface {
 	GetObservation(ctx context.Context) (proto.Message, error)
 }
 
+type BurstObservatory interface {
+	Observatory
+	Check(tag []string)
+}
+
 func ObservatoryType() interface{} {
 	return (*Observatory)(nil)
 }