Update PSR Capacity and Transmission Capacity

[AndBerna]

This PR solves the problem stated at #98

Proposed solution for PSR Capacity

New response object proposed :

• All the different units are now listed under the array fuelSource : A list of the different fuel sources
• unit is now individual for each fuelSource : Different generating plants might have different magnitudes.
• The different capacity updates are now listed under the array capacity for each FuelSource : Historical updates are clearly identified with their corresponding fuelSource.

i.e:
The proposed example shows two producing units:

• One Hard Coal plant with a capacity upgrade
• One Wind Farm with no historical capacity upgrades

Proposed update for PSR Transmission Capacity

• unit should be individual for each transmissionCapacity : Different interconnections might have different magnitudes.

[ssuffian]

I think I'd prefer the unit to be at the top level, it makes it much easier to ingest the data if all of it is coming with the same unit on each call.

[AndBerna]

I think I'd prefer the unit to be at the top level, it makes it much easier to ingest the data if all of it is coming with the same unit on each call.

in terms of readiblity I totally agree with you, but I was worried on how to manage it in PSRs that represent balancing areas where we can have varying magnitudes from nuclear power plants to local solar farms, for instance

[ssuffian]

Maybe we just default to MWh? Most solar farms would be on the order of magnitude of 1 MWh, and a nuclear plant would only be in the thousands then right?

[ssuffian]

I'm also now thinking that we should possibly have separate arrays, one for "capacity" and one for "historical capacity", as I think a very common use case would be to just get the current capacity, so itd be nice to have an easy way to do that.