Film Offset X and Y, and Focus Distance, as controls exposed in Lister for Cameras

Taken from forum post https://forum.corona-renderer.com/index.php?topic=42747.0

"
maybe add the following to the optional columns in the corona lister cameras tab:

- Film Offset X (I could use this in the camera lister when tweaking all the cameras one by one)

- Film Offset Y

- Focus Distance (Very handy to set driver/set driven in xpresso connecting this to the 'near clipping')
"

Added to both Cameras and Workflow & Tools categories. An internal tracking task has already been created for this.