DeFiCh/ain - listaccounthistory should support next with {blockheight,txn-no}

[fuxingloh]

What would you like to be added:

Currently listaccounthistory on DeFiCh/ain. There isn't a way to effectively pagination as you can't provide txn-no as a pagination token. To support slice pagination; we need to be able to provide to all params within the AccountHistoryKey. Address & BlockHeight is currently supported but, txn-no isn't.

Expected feature: listaccounthistory address {next:{blockheight: ..., txn: ...}}

For reference, this is the key.

struct AccountHistoryKey {
    CScript owner;
    uint32_t blockHeight;
    uint32_t txn; // for order in block

To be implemented on https://github.com/DeFiCh/ain first before we implement it here.

/triage accepted
/priority important-soon
/area packages