Use "unicode whitespace" category for smart numeric sorting

[eugenesvk]

This is how files are sorted currenty

• File_ 8 regular space
• File_10
• File_ 8 figure space

This is incorrect, the third file File_ 8 figure space should also come before the second file (figure space is used here so that visually the names have the same width for the name+number portions, though ironically in this web form it seems to be the opposite)

The sorting rules should include all unicode whitespace category when doing the smart sorting of numbers