Implement command line upload

[DBa2016]

Is your feature request related to a problem? Please describe.
Some slicers - e.g. lychee - offer a possibility to call a command on the sliced file. A curl call there would be able to upload a file, however when trying the naive "curl -F 'file=@my_file_name' http://mariner_host/api_upload_file", I am getting a "The CSRF token is missing." error message.

Describe the solution you'd like
Enable upload from other sources than the frontend.

[luizribeiro]

Hey! Doing this over HTTP is probably not a good idea - unless we have a proper API that uses some form of authentication (that does not rely on cookies). Otherwise your mariner instance would be vulnerable to CSRF attacks

Have you considered just using scp to copy your files to your pi? That's what I generally use when I don't want to upload with the UI.