getStorageAt method
Implementation
Future<Uint8List> getStorageAt(EvmAddr address, BigInt slot,
{String block = 'latest'}) async {
final slotHex = '0x${slot.toRadixString(16)}';
final result = await _rpc(
'eth_getStorageAt', [address.toString(), slotHex, block]) as String;
return hexDecode(result);
}