CalBigNotionalInt64() calculate the multiply value of notional based on price and qty both price and qty are in int64 with 1e8 as decimals TODO: here the floor divide is used.

Price ≥1e9 ≥1e10 ≥1e11 ≥1e12 ≥1e13 ≥1e14 ≥1e15 ≥1e16 ≥1e17 TickSize 1e4 1e5 1e6 1e7 1e8 1e9 1e10 1e11 1e12 LotSize 1e4 1e3 1e2 1e1 1 1 1 1 1.

IsExceedMaxNotional return the result that is the product of price and quantity exceeded max notional.

min notional is 1, so we need to ensure price * qty / 1e8 >= 1.