Fixes #7915 - copy uploaded files to shared tmp directory in plan phase

When running foreman-tasks service via systemd, it's process has isolated
`/tmp` directory. Copy the uploaded files to shared location in web server
process before getting to the dynflow executor so that it can read the data.
It's because of https://github.com/Katello/katello/pull/4736/files#diff-acda6ac6712e66fc9557b7631a8befbfR47 , `$ERROR_INFO`, that rubocop suggested over `$!`