I'm sorry to say there isn't any such functionality availability, and it's not something that can be enabled with a few lines of JavaScript or anything similar.
The only thing I could suggest is to use a plugin that adds drag and drop re-ordering of posts. That would normally work by changing the menu_order field value for each post, which could then be used for sorting the posts when displayed.
But that would only work in the normal list of post screens in the WordPress back end, i.e. when listing all Films in the back end, not in the context of the post relationship UI shown in your screenshot.
This need seems so obvious that it's strange that it's not handled by toolset.
Anyway, can you help me by finding an easier way to edit the metas linked to that relationship. Edit is editing the Film, Quick edit is working, but I don't want to edit the films metas, only the relationship metas.