Strongly related to changes in #353

Note: We should disable the simplify wildcard in order to keep most of the generators separately and therefore their costs and efficiencies.

Validation methods

We separate the validation into two steps:

Validation of the Network pre-optimization

[x] Capacity totals per country and carrier for conventionals - remove remaining duplicates (@FabianHofmann )
[x] Renewable capacities from OPSD dataset - per country or all of Europe? (@chrstphtrs, @martacki)
- [x] scaling of existing capacities (exogeneously)
[ ] Revise efficiencies of single plants (heuristics based on commissioning year/country?) (@lisazeyen)
[ ] Must-run conditions for CHPs still need to be quantified ( @chrstphtrs , @FabianHofmann, @Irieo )

[x] Double-check cross-border transmission capacities ( @Irieo, @martacki )
- [ ] How does the spatial resolution affect the simulation?

[ ] Energy mix per country
[ ] Import/Export balances
[ ] OCGT dispatch
[ ] electricity price time series (with one node per bidding zone, NTCs rather than fraction of thermal rating, linearised unit commitment, ramping, CO2 certificate price time series from historical data, heat-led CHP, demand elasticity for energy-intensive industry and updated varied efficiencies of gas plants)