TableReport errors when a column is not sortable

[jeromedockes]

Describe the bug

Since the introduction of the "is sorted" indication in the TableReport it crashes when a column contains a type that cannot be sorted such as lists and structs

Steps/Code to Reproduce

import skrub
import polars as pl


df = pl.DataFrame({"a": [[1, 2], [3, 4]]})
skrub.TableReport(df).open()

Expected Results

a tablereport

Actual Results

polars.exceptions.InvalidOperationError: cannot perform '<=' comparison between series 'a' of dtype: list[i64] and series 'a' of dtype: list[i64]

Versions

main branch