`ipfs add` should have second stage of progress bar for providing

after #4333 gets merged, providing will happen as a post-process step after the import. For large datasets (and a 'provide everything' strategy) this will take a while. Currently this will manifest as ipfs add hanging after its 'done'.

Start with the `ipfs add` command and trace how its current progress bar reports completion after import. Review issue #4333 to understand the post-process providing stage; done means the progress display separately represents providing and no longer appears finished while providing is still running.

Written by the indexing model from the issue text.