getBaseBinPrice(binStep), getBinPrice(baseBinPrice, binId), and
getBinPriceFromStep(binStep, binId) are direct bigint ports of the on-chain Q64.64 price
math. They’re useful for computing a bin’s price without an RPC round trip — e.g. when picking
lowerBinId/upperBinId for a new position before it exists on-chain. getBinPrice/
getBinPriceFromStep return undefined if binId is outside the representable range for that
binStep:
bin_step and bin_id alone.