readline: improve getStringWidth()

1. Simplify the getStringWidth function used by Intl builds by removing
   dead code (the options were unused) and by refactoring the logic.
2. Improve the getStringWidth unicode handling used by non-Intl builds.
   The getStringWidth function returned the wrong width for multiple
   inputs. It's now improved by supporting various zero width characters
   and more full width characters.

PR-URL: https://github.com/nodejs/node/pull/31112


Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>