Blender Git Loki

Fix T65447: Mask doesn't update in compositor unless there's motion blur on

This is probably just one of the related issues.

Root of the problem was that compositor job was using original scene and node
tree for compositing. It is not guaranteed to have all the evaluated data.

Switched compositor job to use it's own render-pipeline-like dependency graph
which has everything evaluated in it.

Reviewers: brecht

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D4998