Allow files added to figshare to automatically be made public

[ethanwhite]

What I did

1. Connected an OSF Project (https://osf.io/86v7t) to a public figshare file set (https://figshare.com/articles/OSFTest/5221261)
2. Added a new file (data4.csv) to the figshare file set via OSF

What I expected

1. The new file would appear in the publicly viewable figshare file set
2. This would trigger a new figshare revision

What actually happened

1. The file did not appear publicly
2. It is viewable when logged in, but to be make it public I would have to do this manually through figshare. We're trying to use https://github.com/dib-lab/osf-cli to automate archiving of files from regularly built pipelines so this manual step isn't viable for our use case.

Suggested solution

Add an option to the figshare item in Configure Add-ons to allow new files to automatically be made public. It is possible to make new files in existing sets public via figshare's API.