JSON-RPC: Add eth_createAccessList RPC call

[MariusVanDerWijden]

WIPPPPP! @timbeiko :D, replaces #196

[MariusVanDerWijden]

@lightclient asked

Is this field optional? If an error is returned, is accessList and gasUsed omitted?

No, this field is not optional. If an error is returned the accessList and gasUsed are still returned. Only if the method creates a real error (state not available, block in the future, ...) then nothing is returned.
Returning the vmErr and the accessList and gasUsed together is still useful in some cases.

[MariusVanDerWijden]

The implementation in geth for this call can be found here:
ethereum/go-ethereum#22550
(Interesting part: https://github.com/ethereum/go-ethereum/pull/22550/files#diff-c426ecd2f7d247753b9ea8c1cc003f21fa412661c1f967d203d4edf8163da344R1332)

Basically we implement the following algorithm:

al <- tx.AccessList // Take the current accesslist 
for {
   al2 <- execute(tx, al) // execute the transaction
   if al == al2 {
      return al // nothing changed between runs 
   }
   al = al2
}

[fvictorio]

This feels inconsistent with the result of debug_traceTransaction, which has the failed and returnValue properties. Would it make sense to use those properties instead?

[lightclient]

@MariusVanDerWijden is this something you're still working on or can it be closed?

[MariusVanDerWijden]

@lightclient I'm not sure, did someone port this to the new spec already? If not I would like to keep it open as a reminder that this RPC call exists

[lightclient]

@MariusVanDerWijden I see this was supposed to replace #196, but that was merged. So I'm not sure this is still a WIP or if #196 adequately describes the method?

I will port any new methods merged to this repo into the eth1-apis repo after London.

[MariusVanDerWijden]

Yeah Tim merged #196 pretty quickly. but I wasn't really finished with the discussions yet, so he reverted the change. The codebase doesn't contain the eth_createAccessList RPC yet.

[lightclient]

@MariusVanDerWijden ah right, I remember now. Should this PR be merged then (i.e. does it accurately describe the endpoint)? I can port it to the new spec once it's merged here.

[SamWilsn]

Should be migrated to https://github.com/ethereum/eth1.0-apis