Gets the limit order pool with token pairs

getLimitOrderPool can gets the limit order pool with coin type of a token pair.

const pool = await sdk.LimitOrder.getLimitOrderPool(
  '0x5d4b302506645c37ff133b98c4b50a5ae14841659738d6d733d59d0d217a93bf::coin::COIN',
  '0xaf8cd5edc19c4512f4259f0bee101a40d41ebed738ade5874359610ef8eeced5::coin::COIN'
)