Unify Checkpoint Writing for ls1 Vanilla and AutoPas

[HomesGH]

So far, there are different molecule formats in ls1. Some are designed to only store information for spherical particles. This way, some space can be saved when using only sperical particles.

What is not very intuitive and user-friendly, is that the molecule format depends on wether AutoPas or not is used. Since AutoPas only handles spherical particles so far, no rotational information are stored in the checkpoint files. When using the default LinkedCells approach, however, another molecule format is used even if the scenario is the very same.

I would suggest that AutoPas writes the same checkpoints as the LinkedCells.
To solve this issue, you can have a look at the AutoPas molecule class in ls1. In all of the molecule classes, there is a method for writing the checkpoints (wether binary or not).

Furthermore, we can think of getting rid of the different molecule formats at least in the writing of the checkpoints. For legacy reasons, we should still consider the molecule format when reading in checkpoints.

[FG-TUM]

Suggestion:

• Move write and writeBinary to MoleculeInterface
• Implement both with getters that are implemented by the derived classes.