Implement n-1 security

[birgits]

Description

In #202 I raised the issue, that we currently don't check n-1 security. On this branch I started an implementation to fix this. However, I didn't have time to finish it.
The idea is, to first run the normal grid expansion without n-1. In a second reinforcement step, n-1 is checked. Therefore, the residual load per MV feeder is determined and feed-in and load in all time steps, where the residual load in the feeder is negative, would be set to zero, so that only load cases (with a positive residual load) are reinforced in the second step, with lower allowed load factors (these are specified in the config files).

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• New and adjusted code is formatted using the pre-commit hooks
• New and adjusted code includes type hinting now
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• The Read the Docs documentation is compiling correctly
• If new packages are needed, I added them the setup.py, and if needed the rtd_requirements.txt, the eDisGo_env.yml and the eDisGo_env_dev.yml.
• I have added new features to the corresponding whatsnew file