Mujoco simulator scroll direction is reversed

[MegaIng]

Summary

The scroll wheel in the simulator has the opposite effect of what is expected from other programs

Expected behavior

Scroll up should result in a zoom in, scroll down should result in a zoom out.

Current behavior

Scroll up results in a zoom out, scroll down results in a zoom in.

Steps to Reproduce

1. Start the simulator
2. Scroll up.
3. See that it scrolls out.

Possible Solution

Check again if this is currently configurable. If not, this may require a larger amount of work similar to #850.