FIP-46: Increase timeout in chain Plugin to increase get_table_rows timeout

Overview

This FIP proposes an update to FIO chain_plugin to increase the timeout placed on get_table_rows queries.

Research and spec

See: https://fioprotocol.atlassian.net/wiki/spaces/FD/pages/546701320

FIP

See: https://github.com/fioprotocol/fips/blob/master/fip-0046.md