Parse scenariofile in constructor and adding helper function to deserialize std::variant-like types.

[ltoenning]

Proposed Changes

For simplification and to avoid the use of wrong data from the scenariofile parser: Directly parse the scenariofile in the constructor.

This PR also adds a function to deserialize YAML entries into std::variant-like types. This will be used in the future for a type-safe list of all different scenario sequence steps.

Definition of Done (optional)

• Feature is implemented
• No known bugs that stops the correct execution
• CI / CD pipeline passed
• The code guidelines were followed
• [ ] Unit and / or Integration tests for the new feature
• [ ] New feature was added to the documentation