feat: add to tagged_table/for neural network

[Gerhardsa0]

Is your feature request related to a problem?

Right now, the nn interface only allows TaggedTable as an input.

For TimeSeries I will add a temporary solution, with to_tagged_table, which converts the TimeSeries into a tagged table. This can also be useful for the future implementation of the InputLayer of the nn Interface.

Desired solution

Right now just a temporary solution and the Integration into the InputLayer Interface.

The lag parameter could also take place here

[Gerhardsa0]

This is not a good way to solve the problem, as the windows are not held as data internally and are more used a schema for the data to load into the tensors.

So some deeper changes will be made.

[lars-reimann]

Seems related to our discussion about input/output layers that handle the conversion from/to tensors. Also seems related to @Marsmaennchen221's work on a DataSet class for images.