BUG: Fix CGF in the rotation method of Gaussian ARD arrays
BUG: Fix CGF in the rotation method of Gaussian ARD arrays

Rotate method was incorrect for Gaussian arrays with more than one
variable axes. The update of CGF in the rotation of Gaussian ARD arrays
did not take into account other variable axes. Now, CGF is multiplied by
the product of variable axes that were not rotated.

SalemAmeen/bayespy,fivejjs/bayespy,bayespy/bayespy,jluttine/bayespy