url: speed up URLPattern

Avoid extra UTF-8 copies on constructor, test, and exec; construct
ASCII V8 strings with NewFromOneByte for regexp matching; and assign
URLPatternInit fields by interned key instead of string-comparing
each component name.

Signed-off-by: Cursor Agent <cursoragent@cursor.com>

Co-authored-by: Yagiz Nizipli <anonrig@users.noreply.github.com>
Signed-off-by: Cursor Agent <cursoragent@cursor.com>

Author: cursoragent