Fix exportWorklistAsZip behavior causing filesystem usage unnecessary growth

When exporting the worklist as a ZIP, if any issue happens while building the ZIP file, the temporary file won't be deleted before the server is restarted. This can lead to a full filesystem if ZIP files are big.

In DocumentListZipExporter.exportWorklistAsZip the temp file will be deleted when the VM terminates:

tmpFile.deleteOnExit();

Several problems appear below this, in the following code:

       try {
            out.close();
            fout.close();
        } catch (ZipException e) {
            return null;
        }
        return tmpFile;

1. there should be a finally statement testing if the returned value will be null, if it is the case then tmpFile should be deleted immediately
2. fout is a FileOutputStream and close() method raises IOException not ZipException
3. out is a ZipOutputStream and close() method can raise IOException as well as ZipException
4. both exception types should be handled and a error message should be added to the logs containing the ZIP filename