[Python-ideas] Add a .whitespace property to module unicodedata

I suggest including a simple str variable in unicodedata module to mirror string.whitespace, so it would contain all characters defined in CPython function [_PyUnicode_IsWhitespace()](https://github.com/python/cpython/blob/main/Objects/unicodetype_db.h#L6314) so that: # existent string.whites

[Python-ideas] Add a .whitespace property to module unicodedata

I suggest including a simple str variable in unicodedata module to mirror string.whitespace, so it would contain all characters defined in CPython function [_PyUnicode_IsWhitespace()](https://github.com/python/cpython/blob/main/Objects/unicodetype_db.h#L6314) so that: # existent string.whites