Use helper method that doesn't throw when no model

When a payment configuration node exists in XML but there is no <model>
defined, getList() will throw an UnexpectedValueException. One use case for
creating such a set-up is a module that provides default configuration
overrides for payment methods which are not installed on the current website.
For example:

<config>
  <default>
    <payment>
      <checkmo>
        <active>0</active>
      </checkmo>
      <not_installed_here>
        <debug>0</debug>
        <environment>production</environment>
      </not_installed_here>
    </payment>
  </default>
</config>

In this case, the payment method 'not_installed_here' does not have a <model>
node defined, as the payment method module is not installed on the website.

Author: fredden

app/code/Magento/Payment/Model/PaymentMethodList.php

@@ -39,26 +39,12 @@ public function __construct(
      */
     public function getList($storeId)
     {
-        $methodsCodes = array_keys($this->helper->getPaymentMethods());
-
-        $methodsInstances = array_map(
-            function ($code) {
-                return $this->helper->getMethodInstance($code);
-            },
-            $methodsCodes
-        );
+        $methodsInstances = $this->helper->getStoreMethods($storeId);
 
         $methodsInstances = array_filter($methodsInstances, function (MethodInterface $method) {
             return !($method instanceof \Magento\Payment\Model\Method\Substitution);
         });
 
-        @uasort(
-            $methodsInstances,
-            function (MethodInterface $a, MethodInterface $b) use ($storeId) {
-                return (int)$a->getConfigData('sort_order', $storeId) - (int)$b->getConfigData('sort_order', $storeId);
-            }
-        );
-
         $methodList = array_map(
             function (MethodInterface $methodInstance) use ($storeId) {