We have a new, improved string type coming up in AK (OOM aware, no null
state), and while it's going to use UTF-8, the name UTF8String is a
mouthful - so let's free up the String name by renaming the existing
class.
Making the old one have an annoying name will hopefully also help with
quick adoption :^)
Effects tab provides the UI for setting SystemEffects.
DisplaySettings is getting a bit crowded and might need a re-org
at some point, but this seems like a good home for effects while
the settings mature.
