Feature / Updated transformer ranking

[Jerry-Jinfeng-Guo]

This PR implements the updated transformer ranking in https://github.com/PowerGridModel/power-grid-model/issues/662

• [x] Unregulated transformer edges get weight 0 instead of 1
• [x] Update unit tests
  • [x] Add unit tests with un-regulated transformers
  • [x] Update existing tests based on new correct results
  • [x] Update docs

[sonarqubecloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
75.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[sonarqubecloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
77.8% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud