[enhance] Replace column selectors with sklearn funcs

[nabenabe0928]

Currently, we are picking columns by ourselves, but since sklearn has its own column selectors, we can use it.

The selectors for numerical and categorical columns can be simply implemented by the following:

import numpy as np
from sklearn.compose import make_column_selector as selector

numerical_col_selector = selector(dtype_include=np.number)
categorical_col_selector = selector(dtype_exclude=np.number)