Regionally differentiated heat pump & electric heater costs using dwelling ratios

[brynpickering]

What can be improved?

Heat pump and electric heater techs introduced in #393 use average costs from various types of buildings (new/existing, single-/multi-family), which are given independently by the Danish Energy Agency. When we have the processing in place to regionalise heat profiles using dwelling ratios (as part of #324?), we should use those same values to weight the single-/multi-family costs.

Version

1.2.0.dev