feat: add estimate_gas entrypoint that doesn't substract gas refunds

[enitrat]

Feature Request

If gas is refunded during the transaction, it's only refunded at the end of a tx. For example, the gas_used could be 20,000, but since we reset a storage slot to 0 we actually benefitted from a gas refund at the end of the tx, and the total gas required to execute the tx is higher.

We should have an estimate_gas entrypoint that doesn't take into account gas_refund and provides the gas required for the tx to complete.