Add: Industry window zoom with mouse wheel

src/industry_gui.cpp

@@ -1131,6 +1131,13 @@ public:
 		}
 	}
 
+	void OnMouseWheel(int wheel) override
+	{
+		if (_settings_client.gui.scrollwheel_scrolling != SWS_OFF) {
+			DoZoomInOutWindow(wheel < 0 ? ZOOM_IN : ZOOM_OUT, this);
+		}
+	}
+
 	void OnQueryTextFinished(char *str) override
 	{
 		if (StrEmpty(str)) return;