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/Services/WindowServer/CMakeLists.txt

@@ -9,7 +9,7 @@ set(SOURCES
     Cursor.cpp
     EventLoop.cpp
     main.cpp
-    MenuBar.cpp
+        Menubar.cpp
     Menu.cpp
     MenuItem.cpp
     MenuManager.cpp