FR: Additional tools and/or help needed in FRED/QtFRED for camera coordinate systems

More specifically, not all of the coordinate systems in FRED align with the camera and orientation code. More documentation and user interface enhancement needs to be done to allow users to operate with the two different coordinate systems without getting confused. They might assume that lessons in one system can be applied to the other, where this is not necessarily the case.

It would be nice to provide a FRED widget to calculate/convert between one coordinate system and another.

[Migrated from Mantis 2023](http://scp.indiegames.us/mantis/view.php?id=2023)

> Admiral MS said the following:I took a look at this and there seems to be no difference between camera and ingame coordinate systems:- I found no transformation anywhere in camera code that would change something from the ingame coordinates- Using a script to display Position and Orientation of a ship and its camera revealed them to be identical (scripting includes no tranformations)- FRED uses the same axes that are used ingameWhat I found:- The background editor in FRED uses a completely different definition of pitch bank and heading that doesn't align with ingame coordinates- The input of set-object-orientation is defined as going from 0 to 360° for pitch, bank and heading while ingame these have different ranges (heading and bank: -90° to 270°, pitch: -90° to 90° to -90°)- Guessing an orientation for a random direction and bank angle is nearly impossible in the system used, it has to be calculated- Before the camera code and scripting were added set-object-orientation was the only sexp that allowed to modify the actual object orientation, so people may have a wrong idea of how the orientation worksObiously there is a chance I missed something - I didn't check every single line of code that is somehow related to cameras.