🐛 Fix accessing the 'alphabets' property when the payload contain surrogate like characters

[Ousret]

Brief:

Accessing the alphabets property of a CharsetMatch instance when the original payload contains a surrogate-like character may raise an unexpected exception.

An example/test case is added to ensure this bad case will not happen again.

[Ousret]

line 211, in alphabets
    self._unicode_ranges = sorted(list(detected_ranges))
TypeError: '<' not supported between instances of 'str' and 'NoneType'

given traceback