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/Applications/Calendar/main.cpp

@@ -34,9 +34,9 @@
 #include <LibGUI/Calendar.h>
 #include <LibGUI/Icon.h>
 #include <LibGUI/Menu.h>
-#include <LibGUI/MenuBar.h>
-#include <LibGUI/ToolBar.h>
-#include <LibGUI/ToolBarContainer.h>
+#include <LibGUI/Menubar.h>
+#include <LibGUI/Toolbar.h>
+#include <LibGUI/ToolbarContainer.h>
 #include <LibGUI/Window.h>
 #include <unistd.h>
 
@@ -71,7 +71,7 @@ int main(int argc, char** argv)
     auto& main_widget = window->set_main_widget<GUI::Widget>();
     main_widget.load_from_gml(calendar_window_gml);
 
-    auto toolbar = main_widget.find_descendant_of_type_named<GUI::ToolBar>("toolbar");
+    auto toolbar = main_widget.find_descendant_of_type_named<GUI::Toolbar>("toolbar");
     auto calendar = main_widget.find_descendant_of_type_named<GUI::Calendar>("calendar");
 
     auto prev_date_action = GUI::Action::create({}, Gfx::Bitmap::load_from_file("/res/icons/16x16/go-back.png"), [&](const GUI::Action&) {
@@ -146,7 +146,7 @@ int main(int argc, char** argv)
         view_month_action->set_checked(true);
     };
 
-    auto menubar = GUI::MenuBar::construct();
+    auto menubar = GUI::Menubar::construct();
     auto& app_menu = menubar->add_menu("&File");
     app_menu.add_action(GUI::Action::create("&Add Event", { Mod_Ctrl | Mod_Shift, Key_E }, Gfx::Bitmap::load_from_file("/res/icons/16x16/add-event.png"),
         [&](const GUI::Action&) {