FEA Add RepeatedStratifiedGroupKFold as a new splitter

[arvkevi]

closes #24247

Reference Issues/PRs

This functionality was discussed in #13621.

What does this implement/fix? Explain your changes.

This adds a splitter class to model_selection that repeats StratifiedGroupKFold n times.

Any other comments?

[github-actions]

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[glemaitre]

I'll provide a review to this feature. Sorry @arvkevi that this PR did not get any attention.

@arvkevi are you still willing to address the review that I'll be doing or you prefer to give the torch to someone else?

[arvkevi]

No worries, I can address the review @glemaitre

[adrinjalali]

I think for this it makes sense to have a repeat kwarg to the constructor and have a variant instead of a new class. Note that with the existing classes we might also merge them together and deprecated some.

[glemaitre]

@adrinjalali I think that we can add the class and the deprecation can come as a whole where we move into parameters instead of separate class.

[glemaitre]

In general, it looks good. Just a couple of nitpicks.