Copy vendor extensions from request body (#6766)

Author: 0x4a616e

modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java

@@ -5863,6 +5863,9 @@ public CodegenParameter fromRequestBody(RequestBody body, Set<String> imports, S
         codegenParameter.description = escapeText(body.getDescription());
         codegenParameter.required = body.getRequired() != null ? body.getRequired() : Boolean.FALSE;
         codegenParameter.isBodyParam = Boolean.TRUE;
+        if (body.getExtensions() != null) {
+            codegenParameter.vendorExtensions.putAll(body.getExtensions());
+        }
 
         String name = null;
         LOGGER.debug("Request body = " + body);