Remove magic numbers

[0xKitsune]

A contant value should be used anywhere there is a U256 value that never changes.

For example:

      //Set sqrt_price_limit_x_96 to the max or min sqrt price in the pool depending on zero_for_one
        let sqrt_price_limit_x_96 = if zero_for_one {
            U256::from("4295128739") + 1
        } else {
            U256::from("0xFFFD8963EFD1FC6A506488495D951D5263988D26") - 1
        };

All of these values should be changed to match this format:

pub const MIN_SQRT_RATIO: U256 = U256([285968860985, 0, 0, 0]);
pub const MAX_SQRT_RATIO: U256 = U256([
    9809463991923573570,
    227557619515130776,
    5049738529920590081,
    1,
]);