K8400 Vertex bottom dual fan duct

Recreated the bottom fan duct to also blow to the second extruder driver.

##### Print in one part:

Rotate -90 degrees around X-axis (fan mount to bed) and print with supports to the bed. Removing the support is a pain!


##### Print in two parts:

Print the seperated parts with no support and glue them together. (I did not try this, but as far I've seen with my print, this should work.)