This is part of the future work of implementing LazyDOMString as
outlined in https://github.com/servo/servo/issues/39479.
We use str() method or direct implementations on DOMString for these
methods. We also change some types.
Signed-off-by: Narfinger <Narfinger@users.noreply.github.com>
Testing: This is essentially just renaming a method and a type and
should not change functionality.
Signed-off-by: Narfinger <Narfinger@users.noreply.github.com>