make dangling object policy and data reference verification policy
parameters
integrate into UploadArtifactResourceImpl for www-form-url-encoded

TODO: integrate with multipart/form-data method
use try-with-resources block
use try-with-resources for other input stream
delete the temporary file when it is closed after uploading, including
if there was an error when uploading
move policy enumerations to podd-api so they can be used in the client