Synfuel update

Created by: fschreyer

Update and refactor CCU module following REMIND-EU implementation. It restructures and documents CCU module. Moreover, techno-economic parameters of synfuel production are adjusted following, among others, Agora (2018, https://www.agora-energiewende.de/fileadmin2/Projekte/2017/SynKost_2050/Agora_SynKost_Study_EN_WEB.pdf) and UBA (2016, https://www.umweltbundesamt.de/sites/default/files/medien/377/publikationen/161005_uba_hintergrund_ptl_barrierrefrei.pdf). It also makes the switch to switch off CO2 storage regional which can be useful for synfuel analyses.