Costs Projection

[Plutoberth]

Basically calculating the costs-output table from the costs table. Given many different resources (Wind, Gas, Coal, PV-{Residential, Utility, Mixed-Use}), their prices, and a projection method (YoY, Linear, etc), calculate the costs for all relevant years (parameterized - not just 2050). The interpolation part was done by @itay-raveh in #1, we just need to define all of the required parameters, find out their sources, and then create classes for them.