feat request: Add Inspecting support for System Transactons

[rezbera]

At the moment, normal transactions have inspecting variants, but system transactions don't have a way to enable inspecting. The system_transaction transaction abstraction is used in bera-reth to add protocol enforced, gas-free, nonce-free transactions at top of block, but we also want it to look like a normal transaction in block explorers and via RPC methods (which is not the case for other system calls like eip4788).
Inspecting doesn't seem to be possible for such transactions. (most frequently used in debug_traceTransaction and debug_traceBlock apis.

Additional Context

In Reth, there exists the Trace trait which is the entry point for transaction traction tracing (see https://github.com/paradigmxyz/reth/blob/818e01773accb34ef807136fec343179678b40b5/crates/rpc/rpc-eth-api/src/helpers/trace.rs#L30-L48)

This eventually calls into alloy-evm as such:

    fn transact_raw(
        &mut self,
        tx: Self::Tx,
    ) -> Result<ResultAndState<Self::HaltReason>, Self::Error> {
        if self.inspect {
            self.inner.inspect_tx(tx)
        } else {
            self.inner.transact(tx)
        }
    }

However, transact system call reaches here, which has we can see has no check for inspect as there is no inspect equivalent for system txs:

    fn transact_system_call(
        &mut self,
        caller: Address,
        contract: Address,
        data: Bytes,
    ) -> Result<ResultAndState<Self::HaltReason>, Self::Error> {
        self.inner.transact_system_call_with_caller_finalize(caller, contract, data)
    }

Looking deeper into the implementations in revm, I don't see an obvious reason why inspect couldn't exist for system txs unless I'm mistaken. Thanks!

[rakita]

iirc this is not shown anywhere in RPC, so there was no reason to add it.

Be free to add it, InspectorHandler should be modified and InspectSystemCallEvm trait added.

[rezbera]

awesome, i'll take it on