LibGUI: Change GUI::KeyEvent::key() type to KeyCode

...instead of a plain int. Yay for some type safety.

DevTools/HackStudio/CursorTool.cpp

@@ -147,6 +147,8 @@ void CursorTool::on_keydown(GUI::KeyEvent& event)
         case Key_Right:
             move_selected_widgets_by(m_editor.form_widget().grid_size(), 0);
             break;
+        default:
+            break;
         }
     }
 }

DevTools/VisualBuilder/VBForm.cpp

@@ -217,6 +217,8 @@ void VBForm::keydown_event(GUI::KeyEvent& event)
                 widget.gwidget()->move_by(m_grid_size, 0);
             });
             break;
+        default:
+            break;
         }
         return;
     }

Libraries/LibGUI/Event.h

@@ -264,14 +264,14 @@ enum MouseButton : u8 {
 
 class KeyEvent final : public Event {
 public:
-    KeyEvent(Type type, int key, u8 modifiers)
+    KeyEvent(Type type, KeyCode key, u8 modifiers)
         : Event(type)
         , m_key(key)
         , m_modifiers(modifiers)
     {
     }
 
-    int key() const { return m_key; }
+    KeyCode key() const { return m_key; }
     bool ctrl() const { return m_modifiers & Mod_Ctrl; }
     bool alt() const { return m_modifiers & Mod_Alt; }
     bool shift() const { return m_modifiers & Mod_Shift; }
@@ -283,7 +283,7 @@ public:
 
 private:
     friend class WindowServerConnection;
-    int m_key { 0 };
+    KeyCode m_key { 0 };
     u8 m_modifiers { 0 };
     String m_text;
 };

Libraries/LibGUI/WindowServerConnection.cpp

@@ -129,7 +129,7 @@ void WindowServerConnection::handle(const Messages::WindowClient::KeyDown& messa
     if (!window)
         return;
 
-    auto key_event = make<KeyEvent>(Event::KeyDown, message.key(), message.modifiers());
+    auto key_event = make<KeyEvent>(Event::KeyDown, (KeyCode) message.key(), message.modifiers());
     if (message.character() != '\0') {
         char ch = message.character();
         key_event->m_text = String(&ch, 1);
@@ -188,7 +188,7 @@ void WindowServerConnection::handle(const Messages::WindowClient::KeyUp& message
     if (!window)
         return;
 
-    auto key_event = make<KeyEvent>(Event::KeyUp, message.key(), message.modifiers());
+    auto key_event = make<KeyEvent>(Event::KeyUp, (KeyCode) message.key(), message.modifiers());
     if (message.character() != '\0') {
         char ch = message.character();
         key_event->m_text = String(&ch, 1);

Libraries/LibWeb/HtmlView.cpp

@@ -316,6 +316,8 @@ void HtmlView::keydown_event(GUI::KeyEvent& event)
         case Key_PageUp:
             vertical_scrollbar().set_value(vertical_scrollbar().value() - frame_inner_rect().height());
             break;
+        default:
+            break;
         }
     }