update and reduce databundle size

[fneum]

• merge electricity-only and sector-coupled data bundles (remove rule retrieve_sector_databundle)
• include rasterised natura.tiff in data bundle (remove rule retrieve_natura_raster)
• remove rule build_natura_raster
• remove outdated files from data bundle (e.g. eurostat energy balances)
• reduce spatial scope of GEBCO bathymetry data to Europe
• remove the use of a separate data bundle for tutorials
• directly download Hotmaps Industrial Database from source (remove Industrial_Database.csv from data bundle)