Include Render Pass name as variable in Filename Format field

When outputting with Custom Render Passes, the Render Pass is automatically added at the end of the output frame file name.

We have a few variables that we can control in the FileName Format section and the RenderPass info is expected to be one of those variables.

I'm referring to the

{world}

,

{frame}

,

{fps}

, etc variables.

This is causing some issues when people are trying to bring these into premier as an image sequence. Premiere expects the frame number to be at the end of the file name.

1. Open any level with a matinee or sequencer sequence
2. Open up matinee or sequencer and select Render Movie
3. Change Capture Type to Custom Render Pass
4. Add a Render Pass (Final Image is fine)
5. Capture movie
6. Navigate to the Output Directory

Result: All files have "_FinalImage" at the end
Expected: An option in the FileName Format field to control where this is located in the file names.