feat: getPaymentProvider接口对外开放

src/PaymentManager.php

@@ -105,7 +105,7 @@ readonly class PaymentManager
         return true;
     }
 
-    private function getPaymentProvider(string $paymentID): PaymentProviderInterface
+    public function getPaymentProvider(string $paymentID): PaymentProviderInterface
     {
         $extension = $this->extensionManager->getExtension($paymentID);
         return $extension->getPaymentProvider();