snafu errors are ugly when mapping from anyhow::Error

[Arqu]

A ProtocolHandler impl now requires the functions to return AcceptError and if the code under it uses anyhow it forces an ugly conversion with .map_err(|e| AcceptError::from(Box::<dyn std::error::Error + Send + Sync>::from(e)))

This could be at least cleaned up a bit with a From<anyhow::Error> implementation even though it's against the grain to have concrete error types for everything, it at least gives an escape latch for devs.