New feature: HTTP reporting for backup+restore, CLI reporting for restore

Hello everyone.

I recently developed HTTP reporting features for Restic: during backups and restores, it sends progress data (how many files processed, how many bytes, how many folders unchanged, etc.) to an external HTTP server every few seconds. I also implemented CLI reporting for restores, in a fashion similar to backups. This was made possible by InAsset, an Italian company who sponsored the development.

I was going to make a PR, but I see that it requires tests and documentation, which were not included in the sponsorship. Is there interest in merging it without those? Alternatively, is someone interested in contributing the tests and documentation?

You can find the changes on my fork: