Add default params_to_tune for encoders transforms

[Mr-Geekman]

🚀 Feature Request

Add default params_to_tune for timestamp transforms.

Proposal

Suggested grid for SegmentEncoderTransform: None.

Suggested grid for MeanSegmentEncoderTransform: None.

Suggested grid for OneHotEncoderTransform: None.

Suggested grid for LabelEncoderTransform:

{
    "strategy": CategoricalDistribution(["new_value", "mean"]),
}

To discuss:

• Strategy "none" won't work properly for some models. For example, LinearPerSegmentModel will fail on None values during prediction.
  • It was decided not to add "none" to the grid.

Test cases

Look at #1221. Check empty grid as well.

Additional context

No response

[ostreech1997]

Closed by #1242.