Add Germany-specific changes and scenario config from Ariadne project

[fschreyer]

Purpose of this PR

This adds some Germany-specific changes and historic fixings in the regipol module and adds the current scenario config of the Ariadne project. The changes are hard-coded and specific for Germany so far and can be generalized more cleanly once we have data and support for that on the global level in REMIND.

Type of change

• [x] Minor change (default scenarios show only small differences)

Checklist:

• [x] My code follows the coding etiquette
• [x] I performed a self-review of my own code
• [x] I explained my changes within the PR, particularly in hard-to-understand areas
• [x] I checked that the in-code documentation is up-to-date
• [x] All automated model tests pass (FAIL 0 in the output of make test)

Further information (optional):

• Test runs are here: /p/tmp/schreyer/Modeling/remind/remind_330/output/KN2045_Bal_2024-05-17_23.48.56
• Comparison of results (what changes by this PR?):