Changes to Raise a new return (RMA) request

added the new optional request property images

removed the request property images

added the new optional request property images[]

the custom_attributes request property type was generalized from object to string

request property package_condition was restricted to a list of enum values

added the new optional request property custom_attributes

added the media type multipart/form-data to the request body

added the new open enum value to the request property package_condition

added the new packed enum value to the request property package_condition