Restructure the existing code.

[Carsopre]

Based upon the initial assessment, we can roughly identify the following points:
• The models use the BMI to interact with the kernels
• There exists common boilerplate to configure how to run the models (environment variables etc.)
• The models can be subdivided in an actual algorithm, and a set of data
• There exists some post processing logic for each model

Based upon these we would suggest the following:

• #40
• #39
• #58
• #60
• Create separate files for each class (potentially divide in directories).
• #53
• #55
• Move the current “run” logic, i.e. the specific values, to runnable example code

Extra based on sonar cloud https://sonarcloud.io/summary/new_code?id=Deltares_NBSDynamics:

• #22
• #23
• #24
• #25