feat(iroh): Add rpc request to add an AddrInfo

[rklaehn]

Description

Add rpc request to add an addr to an endpoint. Without this it is not possible to write some tests using just the client.
Move all node related fns into a separate "node client" and impl deref for it so the fns remain available on Iroh.

Breaking Changes

• iroh::client::Iroh: stats only available via deref from iroh::client::node::Client
• iroh::client::Iroh: connections only available via deref from iroh::client::node::Client
• iroh::client::Iroh: connection_info only available via deref from iroh::client::node::Client
• iroh::client::Iroh: status only available via deref from iroh::client::node::Client
• iroh::client::Iroh: node_id only available via deref from iroh::client::node::Client
• iroh::client::Iroh: node_addr only available via deref from iroh::client::node::Client
• iroh::client::Iroh: home_addr only available via deref from iroh::client::node::Client
• iroh::client::Iroh: shutdown only available via deref from iroh::client::node::Client

Notes & open questions

Change checklist

• Self-review.
• Documentation updates if relevant.
• Tests if relevant.
• All breaking changes documented.