Delete dependency of normalizer

[jordanmontt]

DataFrame should not depend on normalizer

[jecisc]

I talked with Oleks and this is in my todo list :)

I want to remove the normalizer dependency and add documentation about the cools things we have on data processing in Pharo AI like normalizer, partitioner, imputer, and I'm starting an encoder

[jordanmontt]

Yes, super cool :)

[jordanmontt]

I agree with the idea of having a DataFrame structure as clean as possible and then be able to add "plugins" like the normalizer, imputer, etc