Function hydra_dx_math::stableswap::calculate_shares_removed

pub fn calculate_shares_removed<const N: u8>(
    initial_reserves: &[Balance],
    idx_out: usize,
    amount_out: Balance,
    amplification: Balance,
    share_issuance: Balance,
    withdraw_fee: Permill
) -> Option<Balance>

Calculate amount of shares to burn if amount is removed from pool