Add ThreeWindingsTransformerToBeEstimated and TwoWindingsTransformerToBeEstimated (#395)

[sebalaig]

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Does this PR already have an issue describing the problem ? If so, link to this issue using '#XXX' and skip the rest Closes #395

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[sonarcloud[bot]]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
2 Security Hotspots
8 Code Smells

62.6% Coverage
0.0% Duplication

[sonarcloud[bot]]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
2 Security Hotspots
8 Code Smells

62.6% Coverage
0.0% Duplication