Add recursive option to `ipfs files ls`

[kallisti5]

Having a "recursive" option for ipfs files ls would be pretty handy for "finding" data.

I encountered corrupt CID's in #8103.
The corrupted CID's were identified via ipfs repo verify, and I can list the CID's one folder at a time via ipfs files ls -l /, however I have to go directory-by-directory to list them all.

Ideally, ipfs files ls -r -l / would exist so I can dump all the files in MFS, and grep for the CID.