Add option to anonimize data

[ManuelAlvarezC]

Sometimes transfomers are used with sensitive data we don't want the reverse_transform to take the values from nor keep them after extracting its distribution.

In order to do so, we should anonimize data before creating CatTransformer.probability_map, so its mapped to new values taken from faker but preserving its original distribution.

To set this option, there would be two flags on rdt.transformers.CatTransformer.fit:

• anonimize: bool
• category: str

If the flag pii is set, then the values should be mapped with values generated from faker, before generating the probability_map. The supported values of category should be one of the attributes of faker object, that list includes, but is not limited to:

• first_name
• last_name
• name
• ssn
• phone_number
• email