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/LibGUI/TextEditor.cpp

@@ -37,7 +37,7 @@
 #include <LibGUI/Menu.h>
 #include <LibGUI/Painter.h>
 #include <LibGUI/RegularEditingEngine.h>
-#include <LibGUI/ScrollBar.h>
+#include <LibGUI/Scrollbar.h>
 #include <LibGUI/TextEditor.h>
 #include <LibGUI/Window.h>
 #include <LibGfx/Bitmap.h>