This patch changes separates the business logic of fetching from the process of
fetching itself. It does this through a sans-IO approach, where a `Fetcher`
provides the necessary state to help drive a fetch forward, without performing
any of the IO itself.
What the `Fetcher` cares about is:
- What nodes are going to be attempted to be fetched from
- In what order should they be attempted
- When should the fetching process be considered finished
The `Fetcher` is then used in `radicle-cli` to drive forward the `sync::fetch`
function, allowing it to only care about the IO.
Split the commands and change the naming.
* Tracking a repo is now called "seeding"
* Tracking a peer is now called "following"
In this commit, we don't change most of the internal code, only the
user-facing part.
When tracking a repository with the `--fetch` option, we run a fetch
once the tracking is done.
When tracking nodes, we don't accept the `--fetch` flag, as there may
not be a repository to fetch.
Fintan Halpenny
Lorenz Leutgeb
cloudhead
Michail Zampetakis
Alexis Sellier