fix: client login and models

[SKairinos]

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[faucomte97]

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[faucomte97]

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codeforlife/user/auth/backends/username_and_password_and_class_id.py line 15 at r2 (raw file):

class UsernameAndPasswordAndClassIdBackend(BaseBackend):
    """Authenticate a student using their username, password and class ID."""

Update docstring

[faucomte97]

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