Base64 Encoding in Fideslib

[pattisdr]

Bug Description

To fix a recent regression in fidesops, we need the Base64 encoding pieces ethyca/fidesops#700 recently removed from Fidesops ethyca/fidesops#749 to be added to Fideslib.

For example:

class UserCreate(UserUpdate):
    """Data required to create a FidesUser"""

    username: str
    password: str

    --- 
    @validator("password")
    def validate_password(cls, password: str) -> str:
        """Add some password requirements"""
        decoded_password = b64_str_to_str(password) <---***
        if len(decoded_password) < 8:
            raise ValueError("Password must have at least eight characters.")
        if re.search("[0-9]", decoded_password) is None:
            raise ValueError("Password must have at least one number.")
        if re.search("[A-Z]", decoded_password) is None:
            raise ValueError("Password must have at least one capital letter.")
        if re.search("[a-z]", decoded_password) is None:
            raise ValueError("Password must have at least one lowercase letter.")
        if re.search(r"[\W]", decoded_password) is None:
            raise ValueError("Password must have at least one symbol.")

        return decoded_password

Steps to Reproduce

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2. Then This...

Expected behavior

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