Uniform structure for costs integration

[davide-f]

I've noticed that there is the need to smoothly integrate the costs needs among the different technologies of interest:

• customized costs for the US power model, basically the current costs.csv being used potentially fed by technology data as the CI is now integrated
• the costs for heating/cooling
• the costs for egs-related technolgies

A possible architecture is a rule here that collates and integrate the data sources to feed the whole workflow.
Not a priority task now but good to align next monday