DisplaySettings: Replace the monitor image with something more thematic

This is a drawing of my own monitor in a familiar style. :^)

Userland/Applications/DisplaySettings/DisplaySettingsWindow.gml

@@ -7,8 +7,6 @@
 
     @DisplaySettings::MonitorWidget {
         name: "monitor_widget"
-        fixed_width: 338
-        fixed_height: 248
     }
 
     @GUI::Widget {

Userland/Applications/DisplaySettings/MonitorWidget.cpp

@@ -14,7 +14,8 @@ namespace DisplaySettings {
 MonitorWidget::MonitorWidget()
 {
     m_monitor_bitmap = Gfx::Bitmap::load_from_file("/res/graphics/monitor.png");
-    m_monitor_rect = { 8, 9, 320, 180 };
+    m_monitor_rect = { 12, 13, 280, 158 };
+    set_fixed_size(304, 201);
 }
 
 bool MonitorWidget::set_wallpaper(String path)