fix: Better functionality for ipfs add --to-files -w

[ProximaNova]

Make ipfs add + --to-files + --wrap-with-directory work by adding the root CID of what was added to MFS. The is different from past official Kubo which did this: added a literal "." folder to MFS (bug). It's also different from current official Kubo: disallow add to be ran with to-files and wrap. Todo/ideas for this fork: make something like --to-files-cid which only adds root added CID to MFS, whether it's a file, folder, ran with wrap, ran without wrap. (Done: add+to-files+wrap always defaults to adding the CID to MFS and not literal "." and not disabled.)

This update makes perfect sense with --to-files; in other words it does the following:

• Without wrap, the final thing is "[CID] [file/folder name]" -> file/folder name added to MFS.
• With wrap, the final thing is "[CID]" -> CID added to MFS

If a user ran add + --to-files + -w then it's expected behavior to add the final CID to MFS. It being disabled would be unexpected. BTW, https://github.com/ipfs/community/blob/master/CONTRIBUTING_GO.md says something about changing branch name to something other than "master"; I didn't do that.