lib: doing an rpc call to iroh.authors.list() with a fresh iroh data dir results in an error

[Arqu]

If you run

let mut stream = iroh.authors.list().await?;
let x = stream.try_next().await?;

It returns an error Error: RpcError(Table 'authors-1' does not exist)
This is not really an error of the RPC and we should probably not forward that error but return an empty list and possibly log a warn. Ideally that should be initialized on a new iroh data dir without having to fiddle with it.