Make Unicode script fit for future versions

Make Unicode script fit for future versions

Between Unicode 15.0.0 and 15.1.0, the whitespace in
EastAsianWidth.txt has changed a bit, such as from

0020;Na          # Zs         SPACE

to

0020           ; Na # Zs         SPACE

with space around the semicolon.  Adjust the script to be able to
parse that.