`AsImmutable()` does not propagate the `return_str_if_not_expected` param

[tigarmo]

Calling AsImmutable() on a sequence/container does not propagate the return_str_if_not_expected boolean parameter to the recursive calls of the function. That is, the second pytest.raises here fails (and the assertion passes):

def test_return_str_if_not_expected_recursive():
    from oop_ext.foundation.immutable import AsImmutable
    import numpy as np

    with pytest.raises(RuntimeError):
        AsImmutable(np.int32(5), return_str_if_not_expected=False)

    with pytest.raises(RuntimeError):
        assert AsImmutable([np.int32(5)], return_str_if_not_expected=False) == ('5',)