Replace hard-coded scenario names

[ClaraBuettner]

Fixes remaining lines with hard-coded scenario names. Some of the changes are already part of the current run, others are actually not used for the status2019 scenario.

I kept some datasets unchanged since we are not using them in the status2019 pipeline, these are:

• sanity checks
• low flex scenario
• DSM
• industrial_gas_demand
• gas_neighbours