Changes to Download request PDF represented as a Base64-encoded string

removed the media type application/json for the response with the status 400

removed the media type application/json for the response with the status 500

removed the media type text/html for the response with the status 400

removed the media type text/html for the response with the status 500

removed the media type text/json for the response with the status 400

removed the media type text/json for the response with the status 500

api operation id GETv1_Requests_id_pdf_base64-request_id-request_id-request_template_id-reque removed and replaced with GETv1_Requests_id_pdf_base64?request_id=request_id&request_template_id=request_template_id&special_message=special_message&attach_pdf_to_request=attach_pdf_to_request