wacom: Don't call the standard styli "Standard stylus"

The overwhelmingly vast majority of users will never see anything else than a "Standard" (i.e. pen-shaped) stylus. And there's a mismatch between e.g. the Pro Pen 3 being labeled as "Standard stylus" when users spent money on getting a Pro pen.

Let's drop the "Standard" prefix, it adds nothing in this context.