Check if `alephclient crawldir` was 100% successful or not

[sunu]

Sometimes when uploading a large number of documents through alephclient crawldir, a few documents may fail to be processed. But there is no easy way to check.

alephclient should be able to match the processed files on Aleph with the current directory structure to check whether the upload fully succeeded or not. Additionally, we should also be able to retry uploading the failed files only.