Stuff for the Biogenerator

1. Added an option to dispense 50 milk and 50 cream and 5 monkey cubes, since it is relatively annoying for botanists to make small amounts upon small amounts. So now it gives a x5 button.

2. The Ez-nutrient, and the other 2, always only made 3 of it instead of 5 when you used the x5 button. That has been fixed.

3. Added Plant-B-Gone and Pest Spray to the biogenerator. Note, these are only their chemicals and come in 50 unit bottles.

4. Now also able to create carpet floortiles in stacks of 1, 10, 30, and 50.

I tested everything locally, and everything works as intended.
I'm afraid this isn't acceptable. You should add an argument which determines how many objects to build. By having the A HREF link like this: "item=carpet;amount=10". You can then get the amount using href_list["amount"] in the Topic() and then pass it as an argument into this method.

You must remember to do these things:

* Check it is a number.
* Check that if you have enough resources to build them.
* Make sure it is not negative.
* Make sure there is only a single section which checks all of this stuff. It should never be in each if().

It seems like a lot of work but if you do this these are the benefits:

* Much easier to add multiple build options to future objects.
* Less duplicated code makes it easier to fix bugs and maintain.

You can find more information on our standards in [CONTRIBUTING.md](https://github.com/tgstation/-tg-station/blob/master/CONTRIBUTING.md).