[Service API] CMS content export service cannot export CMS content

Description

Preconditions:

• Install and configure the Service API
• Quicksilver site has cms data

Steps to reproduce:

1. Run the CMS Bulk Export method.
   episerverapi/commerce/export/site/ {siteName}

   => System returns a response.

2. Save the response to an episerverdata file.
   
3. Open the exported file.

Expected:
CMS data in the exported file.

Actual:
No CMS data in the exported file.