Everywhere: It's now "Foobar", not "FooBar", and not "foo bar"

I hereby declare these to be full nouns that we don't split,
neither by space, nor by underscore:

- Breadcrumbbar
- Coolbar
- Menubar
- Progressbar
- Scrollbar
- Statusbar
- Taskbar
- Toolbar

This patch makes everything consistent by replacing every other variant
of these with the proper one. :^)

Userland/Libraries/LibGfx/SystemTheme.h

@@ -148,7 +148,7 @@ enum class PathRole {
     TitleButtonIcons,
     InactiveWindowShadow,
     ActiveWindowShadow,
-    TaskBarShadow,
+    TaskbarShadow,
     MenuShadow,
     TooltipShadow,
     __Count,