Add receipt log for EVM triggered transfer

[yangzhe1990]

Block receipts captures important outcomes of the transaction. I think vm triggered transfer, such as balance withdrawal from contract, contract destruction refunds, gas sponsor refund, storage sponsor refund are are important. This can be done at the level of evm transact function.

[yangzhe1990]

From @ChenxingLi: log is user defined, so it's rational with or without log for balance withdrawal.

I think for our defined behavior, such as contract destruction refund and in internal contract, it's still good to have log for triggered transactions.

User and conflux-scan may find it useful.

[fanlong]

@yangzhe1990 , after my experience with the block reward record. I am not sure whether we should put it into receipt/log. Or alternatively, we can just maintain some full node data to enable queries.

The only advantage of log is to perform Merkel proof for a light node. I do not see this is necessary for event triggered transfer histories.

[yangzhe1990]

Let's say if confluxscan displays more information for a contract destruction, and so it need to make some queries, I think the blockreceipt/log is still the place for such information.

What's your take away of trying add block reward record? Is it inconvenient to put data into log?