check compatibility with ABC module

use an ABC mixing like

```python
class DynamicsMixin(abc.ABC):

    @property
    @abc.abstractmethod
    def timestep(self) -> float: ...

    @property
    @abc.abstractmethod
    def sampling_rate(self) -> int: ...
```

and then a dataclass `class(znflow.Node, DynamicsMixin)` that does not overwrite the abc methods.