Rollback dataclass approach

[henhuy]

This came up at #180 (comment)

Idea:
I came to the conclusion, that we should rollback implementation of dataclass facades. I do not vote going back all the way to kwargs, but instead make a mix of required, keyword-only arguments, optional arguments and kwargs.

Explanation:
The whole dataclass approach makes it very hard for inheritance (even if it was my idea originally to introduce them).
Spend way too much time to get it working last time.
The problem with dataclasses is, that they don't allow kwargs.
but we wanted to allow them in facades, so we implemented dataclass_facade which takes all parameters compares them with original dataclass parameters, puts the diff aside, initializes dataclass and adds kwargs from diff afterwards.
The problem with a child facade is, that once we added new parameters in child facade, the algorithm from above is not working anymore and initialization gets more and more complicated (decorator of child class -> init child class ->decorator of parent class -> init parent class) and it is very hard to debug.
For some reason decorator from above (see comment from above) worked, instead of dataclass_facade, but right now I cannot remember why.

[Bachibouzouk]

This is exactly what I struggled with, wanting to use inheritance for a Facade ^^

[Bachibouzouk]

Following discussion at the last oemof-dev meeting and after another discussion with @Ludee, @srhbrnds and @uvchik we also support the idea of stripping the Facade class from oemof-tabular to insert it within oemof-solph. As this will probably make breaking changes within oemof-tabular, we can seize this opportunity to tackle the dataclass issue and at the same time make oemof-tabular fully compatible with FAIR-Data.

It would be good to have as many people as possible involved in laying out/criticizing the structure of the Facade class.

This will then solve the oemof-network dependency problem we currently have with oemof-tabular @gnn, @srhbrnds

(I am not sure where is the best place to have this discussion, I just wanted to make sure people know about this current momentum)