Column selection

[lars-reimann]

Is your feature request related to a problem?

Currently, we can only select columns of a table by name.

Desired solution

• Add support for polars's column selectors.
• New class ColumnSelector with the appropriate static methods.

Possible alternatives (optional)

No response

Screenshots (optional)

No response

Additional Context (optional)

Using callbacks to create a column selector provides little benefit, as we can only validate the finished selector (due to negation, intersection, ...).