Nuke: loader context

[64qam]

When opening a loader in a shot, then change the context in the loader, it opens in the last context. But when changing work files to another shot, the loader remains at the shot where it has been opened last time. The loader is not reset to a shot corresponding to the work file which is confusing.

[create-issue-branch]

Branch bugfix/1074-nuke-loader-context created!