Split generators and refactor namespace generation (#168)

* Avoid building the sames classes twice

* Split generators

* Refactor Helper

Author: jderusse

Result/ListLayerVersionsResponse.php

@@ -138,7 +138,10 @@ protected function populateResult(ResponseInterface $response, HttpClientInterfa
                     'CompatibleRuntimes' => (function (\SimpleXMLElement $xml): array {
                         $items = [];
                         foreach ($xml as $item) {
-                            $items[] = ($v = $item) ? (string) $v : null;
+                            $a = ($v = $item) ? (string) $v : null;
+                            if (null !== $a) {
+                                $items[] = $a;
+                            }
                         }
 
                         return $items;

Result/PublishLayerVersionResponse.php

@@ -133,7 +133,10 @@ protected function populateResult(ResponseInterface $response, HttpClientInterfa
         $this->CompatibleRuntimes = (function (\SimpleXMLElement $xml): array {
             $items = [];
             foreach ($xml as $item) {
-                $items[] = ($v = $item) ? (string) $v : null;
+                $a = ($v = $item) ? (string) $v : null;
+                if (null !== $a) {
+                    $items[] = $a;
+                }
             }
 
             return $items;