Simplify and restructure manager classes

[ltoenning]

⚠️ This PR depends on #116 which must be merged first ⚠️

Proposed Changes

Simplification of the manager classes:

• Using the CoreNetwork class for network setup
• New manager base class which initializes the logging and random generator and runs the simulation
• For simplicity and flexibility, the entire node setup is moved into the individual manager classes
• Using the new scenariofile classes/parser

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 -> The manager is currently not documented at all. I've already started creating documentation, but this will go into another PR.