Also find correct column width of wide characters.
Use unicodedata.east_asian_width() to determine wide/full width
characters if available. Otherwise, return character count as before.
% basic
% unknown
*** [alias] unknown: command bargle is unknown
% ambiguous
*** [alias] ambiguous: command s is ambiguous
% recursive
*** [alias] recursive: circular dependency on recursive
adding foo
% with opts
C foo