Make the workflow more technology-agnostic

[timtroendle]

Currently, there are exactly four technologies, two of which are competing on land (onshore wind and solar farms). These four technologies (including the competing ones) are baked into the analysis early on when land elgibility is determined here.

This has two problems. First, the workflow is not as technology agnostic as it could be. Adding or removing technologies is difficult. Second, it mingles the competing technologies in an error-prone way (all pv/wind-prio things in following rules and output files, like here).

A cleaner solution would be to assess all technologies in isolation, and decide between competing technologies only at the very last step. For example, instead of a integer-map with Eligibility categories baked in, we'd create four boolean-maps:
build/technically-eligible-land.tif (with values 0, 250, 180, 110, 40) -> build/technically-eligible-land-{technology}.tif (with values 0 and 1).

All other maps accordingly. Again, this'll create many more maps and will require more disk space, but workflow code and result data will be much cleaner, hopefully lead to fewer miss-uses, and allow to introduce other technologies more easily.

[timtroendle]

Should disk space become a problem, we should start using compression. Some datasets contain a lot of redundant data and thus we should be able to reduce disk space a lot without increasing runtime much.