Avoid duplicate schemas, fix name generation

Duplicate schema names would generate User_2 -> User_2_3 -> User_2_3_4 etc, this fixes that and also detects duplicate schemas and uses the existing one if found

Service/DocumentationService.php

@@ -256,22 +256,32 @@ private function addSchema(string $name, EntityMapping $mapping, array &$compone
             }
         }
 
+        $newSchema = new OASv3\Schema(['properties' => $properties]);
+
         // try to find a name that has not been used yet
         if (isset($components[$name])) {
-            $appendix = 2;
+            /** @var OASv3\Schema $existingSchema */
+            $existingSchema = $components[$name];
 
+            if ($existingSchema->toJson() === $newSchema->toJson()) {
+                // schema already exists, return existing name
+                return $name;
+            }
+
+            $appendix = 2;
             while (true) {
-                $name = $name.'_'.$appendix;
+                $newName = $name.'_'.$appendix;
 
-                if (!isset($components[$name])) {
+                if (!isset($components[$newName])) {
+                    $name = $newName;
                     break;
                 }
 
                 $appendix++;
             }
         }
 
-        $components[$name] = new OASv3\Schema(['properties' => $properties]);
+        $components[$name] = $newSchema;
 
         return $name;
     }