Fetch missing from server
This changeset introduces a feature where we compare local ids to remote ones and fetch all new documents. Without priority queue or concurrency yet due the lack of code for it (unrelated to this issue).
Also, a bug was temporarily fixed. We were returning the size padding as doc content on get. A commit was added to consider the decrypted size as the real size. It should be enough for now, but #8814 (closed) should look for a better solution.
Bonus: Somehow a closed FD error only affected this code. It's fixed.
- Related: #8808 (closed)
- Related #8814 (closed)