Add support for data batchlization of structures with different shapes of kpoints and eigenvalues.

[floatingCatty]

Background

Now errors will occur when people load the dataset, therefore batching structures with different shapes of points and eigenvalues. This should be supported in the latest updates.

Describe the solution you'd like

This might be resolved by utilizing the nest tensor format. But this would require modification of a lot of data-related things. including but not limited to:

1. The auto data type checking, including the checking in initialization and checking after batching.
2. The information generated when doing batchlization, which records how to recover separate subgraphs from the combined batch.
3. The Cat dims when doing catechization.
4. The impact of changing the default type of some tensors to nested tensors. This might affect some computation steps, such as the loss function part.
5. In The data loading part, some values need to be loaded as nested tensors by default.

Additional Context

No response