Push is not persisted

[mixmix]

ssb-blobs tracks blobs it has pushed to other peers in a level fb (set).

it looks like code currently does not load current state from that db on startup, which means if you attach a blob while offline and then restart your app, the push of that (i think) is forgotten.

Should be easy to test!

[mixmix]

Bonus would be to update the set db to track which peers have taken the blob so far. This way you when. You restart the stack you don't need to try and always hit your push quota so hard, and might save trying to push blob on pērā anō you've already foisted it on