Have an option to send "complete" request when all chunks have been uploaded

[nl-emmanuellodovice]

Thank you for this wonderful project.

It would be helpful if we have an option to send one final request after all chunks of a file have been uploaded so that the server can combine them already. The complete event works but this is only fired when all files have been uploaded which means you will have to wait for all files to be uploaded to send the request. The fileSuccess event also works but then the library sees the file to be completely uploaded already even if it has not been combined yet. It would be nice if we have a completed request that can be seen as one of the chunks but only sent when all chunks have been uploaded.