Enhancements for tasks: "mixing ingredients" and "medical disaster"

[JonasPTFL]

1. Adds particles to the valves of medical disaster, which indicate the leakage of dangerous chemicals. If the valve is closed, the particles will stop spawning.
2. Adds a time indicator to the medical disaster task, that indicates, how much time is left to fix the leakage. The indicator is represented by the level of the chemicals in the pipes. The level of the chemicals decreases as the time passes and the chemicals leak out. If the level reached the bottom and the valves are not closed yet, all chemicals are released from the pipe, the time is over and the task is failed.
3. Adds 1 new spawn point for the mixing ingredients task and 3 new spawn points for the medical disaster task