Whenever the node fetches new updates, it checks if canonical references can be
updated. The node has learned how to return these results and emit them as node
events. This is a breaking change since it adds a new variant the `Event` type,
which is not forwards-compatible.
The `winpipe` crate which is our current best bet for support on Windows
requires that named pipes are at the magical location `\\.pipe\`.
Provide a default on Windows that matches this, and use our freshly
assigned IANA service name for it.
This is a breaking change, as we remove a `pub const`, it should be
reasonably easy to fix by dependents, and probably it was a mistake to
make the default `pub const` as dependents should call `Home::socket`
anyway.