[Feature] Support arbitrary subscription ids

[mattsse]

Component

provider, pubsub

Describe the feature you would like

this currently only supports u256 ids:

alloy/crates/pubsub/src/managers/in_flight.rs

Lines 58 to 70 in 4a270df

	pub(crate) fn fulfill(self, resp: Response) -> Option<(U256, Self)> {
	if self.is_subscription() {
	if let ResponsePayload::Success(val) = resp.payload {
	let sub_id: serde_json::Result<U256> = serde_json::from_str(val.get());
	return match sub_id {
	Ok(alias) => Some((alias, self)),
	Err(e) => {
	let _ = self.tx.send(Err(TransportError::deser_err(e, val.get())));
	None
	}
	};
	}
	}

and causes issues where servers don't return u256 as subscription ids #1155

TODO

• introduce a new type that can handle both u256 and string:

pub enum SubscriptionId {
	/// Numeric id
	Num(U267),
	/// String id
	Str(String),
}

and use this as a replacement for the server_id: U256 where used:

alloy/crates/pubsub/src/service.rs

Line 170 in 4a270df

fn handle_sub_response(&mut self, in_flight: InFlight, server_id: U256) -> TransportResult<()> {

Additional context

No response

[DaniPopes]

alloy/crates/json-rpc/src/common.rs

Lines 26 to 33 in 4a270df

	pub enum Id {
	/// A number.
	Number(u64),
	/// A string.
	String(String),
	/// Null.
	None,
	}

[HowHsu]

As a beginner: why do we use an Enum rather than directly use String as Id