util: improve getStringWidth performance

This makes sure the common path does not normalize the input string.
It's only required for characters that are outside of the ASCII range.

Signed-off-by: Ruben Bridgewater <ruben@bridgewater.de>

PR-URL: https://github.com/nodejs/node/pull/33674


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Anto Aravinth <anto.aravinth.cse@gmail.com>