Remove the Dataset logic from PGM core, use DatasetHandler for MainModel

[TonyXiang8787]

Background

Currently we use Dataset as the input view for MainModel, such as:

https://github.com/PowerGridModel/power-grid-model/blob/95212803cd9af486066deeea4d334b558ccf6e1a/power_grid_model_c/power_grid_model/include/power_grid_model/main_model.hpp#L101-L102

The C-API receives DatasetHandler, we have a function to export to a Dataset. See blow:

https://github.com/PowerGridModel/power-grid-model/blob/95212803cd9af486066deeea4d334b558ccf6e1a/power_grid_model_c/power_grid_model/include/power_grid_model/auxiliary/dataset_handler.hpp#L69-L71

This conversion is redundant. We already have DatasetHandler which handles datasets.

Adjustments

1. Create export function in DatasetHandler to export a std::span for a single component.
2. Remove export_dataset function in DatasetHandler.
3. Change the constructor, get output, and update function of MainModel to receive range of a certain component type.
4. Create a new class OwningDataset to contain owned buffers. This can be used for the validation test and later for the serialization-to-serialization API for the C-API. (msgpack input -> msgpack output).

[mgovers]

@TonyXiang8787 how much of this is still relevant / unblocked with the new constexpr metadata from #475 ?

[TonyXiang8787]

@mgovers still quite relevant