Implementation learning of electrolysis and DAC + CCU on by default

Created by: fschreyer

This pull request should address this issue on synfuels, H2 and DAC. It adds:

• endogenous learning for electrolysis and dac
• a small bugfix for learning
• switches on CCU by default

It was tested with SSP1,2,5 and baseline to policy runs (no recalibration done, as these changes should not have a significant impact on BAU).