Function price_investment_set 

fn price_investment_set(
    investment_set: &InvestmentSet,
    model: &Model,
    solution: &Solution<'_>,
    year: u32,
    shadow_prices: &CommodityPrices,
    annual_activities: &mut Option<HashMap<AssetRef, Activity>>,
    result: &mut CommodityPrices,
)

Calculate prices for the markets in an investment set, updating result.