Qt: implement flow layout game grid

This will allow us to properly style the grid and also remove the need to refresh the whole grid on a window resize

bin/GuiConfigs/Skyline.qss

@@ -678,3 +678,24 @@ QLabel#debugger_frame_pc {
 	color: #000; /* Font Color: Black */
 	background-color: #00ff00; /* Green */
 }
+
+/* Game Grid */
+#game_list_grid_item[selected="true"] {
+	background: #4343c1;
+}
+#game_list_grid_item:focus {
+	background: #4343c1;
+}
+
+/* Game Grid hover and focus: we need to handle properties differently when using descendants */
+#game_list_grid_item[selected="true"] #game_list_grid_item_title_label {
+	background-color: #4343c1;
+	color: #FFF;
+}
+#game_list_grid_item[hover="true"] #game_list_grid_item_title_label {
+	color: #4343c1;
+}
+#game_list_grid_item[focus="true"] #game_list_grid_item_title_label {
+	background-color: #4343c1;
+	color: #FFF;
+}