Enable CustomFinancialModel to get costs from PySAM

[jaredthomas68]

The financial model must be consistent across all technologies, but the wave energy requires the CustomFinancialModel class. HOPP uses the SingleOwner financial model to get PV (and other tech) costs. Thus, when using CustomFinancialModel the PV costs are not available.

We need to update HOPP such that PySAM costs can be accessed when using the CustomFinancialModel class. This could be possibly done by inheriting from the SingleOwner class or by creating methods in CustomFinancialModel to access PySAM costs.

[kbrunik]

Addressed in jaredthomas68#2

• Creates new method set_overnight_capital_cost() in PowerSource to add technology costs.
• Modified set_overnight_capital_cost() for Battery class, includes energy_capital_cost and power_capital_cost

Ideally in the future we can pull ATB costs directly from an API or other method. There is an outdated ATB json in HOPP (2020), could potential update to most recent ATB but not sure if that's the best path.