Remove BIGCC, BIGCC + CCS and fuel cells from FTT:Power

[Femkemilene]

In the recent update of FTT:P, it became clear that BIGCC (Biomass-based integrated gasification combined cycle) and fuel cells lack data, and are not taking off.

I believe our calculations are O(N) to O(N**2), so removing three technologies may speed up the code by 10-25%. We can do this in our current Python update, but we need some capacity to do this in the FORTRAN version as well. Opening up this issue to ask if there are any objections to this? Or if we require a deeper rethinking of our classification.

[Femkemilene]

Had a chat with JF on the topic. The original classification was based on the IEA´s projected cost of electricity production. As the IEA no longer provides information for BIGCC, I don´t see any reason to keep the technology, as it complicates updating the standard solid biomass technology. Fuel cells are still mentioned, but it is unclear what technology they represent, so I would like to still remove this one.

[pv-camecon]

Alright, agreed on (B)IGCC given that we don't have specific data for them (generation nor costs). However, after thinking a little bit I'd argue to keep (presumably stationary) fuel cells in the list. While an unlikely candidate for future power systems, there are a few nations focussed on fuel cells. We'd therefore need to be able to represent them in some of our work.

[Femkemilene]

Another one we may wish to remove is IGCC (integrated gasification combined cycle). The 2020 IEA cost data no longer have this a separate category. This gives us some space to include storage technologies or wind+storage/solar+storage into the model. The IGCC data is based on older data, and we do not have any shares data for the technology.