Add support for FlatCallTracer

[mattsse]

Describe the feature

ref #201 might require some helper for TracingConfig

blocked by #10989

we now have a new variant:

reth/crates/rpc/rpc/src/debug.rs

Lines 392 to 396 in c42d544

	GethDebugBuiltInTracerType::FlatCallTracer => {
	return Err(
	EthApiError::Unsupported("Flatcall tracer is not supported yet").into()
	)
	}

that behaves exactly as the parity tracer, so we can reuse that impl:

reth/crates/rpc/rpc/src/trace.rs

Lines 341 to 358 in c42d544

	/// Returns all traces for the given transaction hash
	pub async fn trace_transaction(
	&self,
	hash: B256,
	) -> Result<Option<Vec<LocalizedTransactionTrace>>, Eth::Error> {
	self.inner
	.eth_api
	.spawn_trace_transaction_in_block(
	hash,
	TracingInspectorConfig::default_parity(),
	move |tx_info, inspector, _, _| {
	let traces =
	inspector.into_parity_builder().into_localized_transaction_traces(tx_info);
	Ok(traces)
	},
	)
	.await
	}

Additional context

No response

[0xkrane]

can take this

[mattsse]

unblocked now