Include these packages in `github.com/anacrolix/torrent` and/or split `metainfo` out of it ?

Hello, I am considering packaging [qbittorrent-cli](https://github.com/ludviglundgren/qbittorrent-cli) in Debian, which depends on a few packages from `github.com/anacrolix/torrent`. In Debian, we package each libraries independently, so I would have to package `torrent`, and while checking a bit the dependency graph, it contains at least one cycle the `github.com/anacrolix/dht/v2` module depends on `github.com/anacrolix/torrent`, and vice-versa. This makes the packaging in Debian more complicated.

I would like to suggest two solutions for this, which are not exclusive:

1. Include `dht/v2` in `torrent`, this would be an easy way to brake the cycle. It makes sense to me as the `torrent` module already holds a lot of different packages.
2. Split out some basic parts from `torrent` in a new repo (e.g. `torrentutil`), mostly `metainfo` and its dependencies, to create a common module to import from both `torrent` and others like `dht/v2`, but also qbittorrent-cli. `torrent` would keep the features mostly related with a bittorrent client while the new module would have less dependencies and only provide useful types and parsers/encoders.

What do you think about this?

N.B. I did not fully investigate the dependency graph of `torrent` so there might be more cycles.

Start by mapping the dependency graph between github.com/anacrolix/dht/v2 and github.com/anacrolix/torrent, including metainfo and its dependencies. Compare the two proposed module arrangements with the needs of qbittorrent-cli; done means agreeing on a structure that removes the cycle and preserves the required library imports.

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