Add auto named group generated when dropping a vehicle onto new group button

src/group_gui.cpp

@@ -999,6 +999,16 @@ public:
 				}
 				break;
 			}
+			case WID_GL_CREATE_GROUP: { // make new group with vehicle specific name and add vehicle
+				const VehicleID vindex = this->vehicle_sel;
+				this->vehicle_sel = INVALID_VEHICLE;
+				this->group_over = INVALID_GROUP;
+				this->SetDirty();
+
+				DoCommandP(0, vindex | (_ctrl_pressed ? 1 << 31 : 0),0 , CMD_CREATE_GROUP_AUTO_NAME, nullptr, nullptr);
+				
+				break;
+			}
 		}
 	}