Evaluate the `warn!` logging in `radicle-protocol`.
If the event is a result of something being suspicious in the running
of the protocol, then it remains a `warn!`.
However, if the system ends up ignoring the event and can continue
without issues, the log level is reduced to `debug!`.
Remove `fn deserialize` and instead provide a trait `fn decode_exact`
for testing.
Refactor errors, so that we can now cleanly distinguish between
`Error::UnexpectedEnd` which means that decoding might work given
more data, and `Error::Invalid`, which means that no amount of
additional data will decode.
While at it, cleanup the variants of `Error::Invalid`, and provide `ControlType`.
What made the issue fixed in the parent commit harder to spot
for me was the multitude of concepts and terms involved in
encoding: What's *serializing* vs. *encoding*? Why is there
this odd `Frame::to_bytes`?
So I decided to clean up a bit. I removed `fn serialize` so that the
logic stays close to the data, and instead of it provide
`fn encode_vec` in `trait Encode` so that we don't add up with
one-offs like `Frame::to_bytes` again.
Also we make use of `encode_vec` in the tests.
Mostly changes of `use`s and moving components to `radicle-protocol`,
with the goal of just getting `radicle-node` to work on top of the new
`radicle-protocol` crate.