With this change, the full gas loop of a transaction can be tracked going from initial balance (`gasLimit`) back down to 0.
I validated on my regression test suite that those conditions applied to all transactions I have:
- First `OnGasConsumed` is always going from 0 -> `trx.gasLimit`
- Last `OnGasConsumed` "new value" is always 0
- trx.gasLimit - last balance of last `OnGasConsumed` is equal to `trx.gasUsed`
The addition of `reason` make it possible for a logger to filter out unwanted signal, for example one could want to drop all OpCode related gas change and only cares about "transaction" level. The reason is also a good thing for visibility and for creating powerful debug tools for Ethereum transaction execution.
Also, I would like that we change the `OnGasConsumed` logic from `OnGasConsumed(actual, cost uint64, reason)` to `OnGasConsumed(old, new uint64, reason)`. With the new tracing I've done, we now have negative `cost` that needs to be passed around but the `cost` is `uint64` so it creates overflow. Everything works fine if you record the new/old value `gas-cost` as the final value goes back to a valid range. But it's weird for consumer that would log `cost` that it's `18127127187219...`. An alternative would be to accept a `int64` for the cost which is also valid, not full coverage theorically but I don't see why an operation would cost more than i64 max value. Maybe it make more sense than to have signature `OnGasConsumed(gas uint64, cost int64, reason)`, I'm fine with it also, I leave the decision to you.
Previously, the makeCallVariantGasCallEIP2929 charged the cold account access cost directly, leading to an incorrect gas cost passed to the tracer from the main execution loop.
This change still temporarily charges the cost (to allow for an accurate calculation of the available gas for the call), but then afterwards refunds it and instead returns the correct total gas cost to be then properly charged in the main loop.
