Consider exporting additional types from arti-client

On IRC, kpcyrd reports

2025-02-10 23:40:10	kpcyrd	some feedback for "using arti-client as a library", I did my first library update today, and it'd be neat if the arti-client crate could re-export some of the types, I needed to edit 7 dependencies for the update :)
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2025-02-11 09:39:17	kpcyrd	I'm using tor_cell::relaycell::msg::Connected, tor_config::ExplicitOrAuto, tor_hsservice::StreamRequest, tor_keymgr::config::ArtiKeystoreKind, tor_proto::stream::IncomingStreamRequest, tor_rtcompat::PreferredRuntime
2025-02-11 09:39:27	kpcyrd	so from each of those crates I pull about 1 type
2025-02-11 09:40:47	kpcyrd	ah, also tor_hsservice::handle_rend_requests and tor_proto::Error
2025-02-11 09:41:25	kpcyrd	and then from arti-client I use `arti_client::{config::{onion_service::OnionServiceConfigBuilder, TorClientConfigBuilder}, TorClient}`

We should decide which of these types would make sense to re-export from arti-client (there are likely other types, not mentioned here, that are worth re-exporting too).