Feature request: Pass stream errors through to callbacks

[insipx]

This should make handling stream errors possible from the SDK's

Need a good way to pass a Result<> through the FFI boundary for uniffi & napi. This could either be by using the traditional Result type or crafting some custom type for XMTP Stream errors.

the fn signatures in question:
pub async fn stream_conversations
pub(crate) async fn stream_messages
pub async fn stream_all_messages
pub fn stream_conversations_with_callback
pub(crate) fn stream_messages_with_callback
pub fn stream_all_messages_with_callback

the with_callback variant is just the non-with-callback variant, except they take a callback and iterate on the stream in a spawned tokio task. This makes it more ergonomic for native client sdks to use the stream, since these native SDK's have no notion of a rust Stream type.

Notice, that in the with_callback variants, instead of passing the error into the callback, we instead match on the result and log an error. This makes it difficult/impossible for external SDKs to handle stream errors. we need a way to pass the error into the callback that is compatible with uniffi and napi

these bindings are in bindings_node/ and bindings_ffi/ folders respectively.

This will allow external native SDK's to handle stream errors rather than silently failing if an error occurs in a stream.