Please fix IVA transforms so that they are aligned to pod's root transform

[sumghai]

Currently, the transform for the IVA spaces in the game uses its own coordinate system. I suspect this was because originally, the player isn't supposed to be able to look out of the window of the command pod.

Please change the IVA transform setup so that its coordinate system is aligned to the root transform of the command pod / crew cabin external part it is paired with, as it would contribute to fixing the following issues:

- Transparent Pods: Although add-ons like JSI RPM have implemented shaders to make see-through command pod windows, the problem is that a large number of unintuitive workarounds were required to make this work, and it is currently not possible to sit in one transparent pod, look out of the window and see into the contents of another transparent pod (the current IVA transform setup causes Kerbals in other pods to be doubled up/oriented incorrectly)

- IVASun orientation: Because the current IVA transform is not oriented in relation to the actual position of the pod/cabin part, the sunlight shining through the windows are incorrect (i.e the sun is starboard, but the light appears to come from the port side)

- "Black backgrounds" in IVA portrait cameras: In some command pods where there is a bubble canopy / window directly behind the Kerbal pilot, instead of seeing the outside of the craft, the view beyond the window is pitch black. Again, this is due to IVA transforms being different from part transforms.