Support file-less scenes. Add scene split, merge and reassign file (#3006)

* Reassign scene file functionality
* Implement scene create
* Add scene create UI
* Add sceneMerge backend support
* Add merge scene to UI
* Populate split create with scene details
* Add merge button to duplicate checker
* Handle file-less scenes in marker preview generate
* Make unique file name for file-less scene exports
* Add o-counter to scene update input
* Hide rescan for file-less scenes
* Generate heatmap if no speed set on file
* Fix count in scene/image queries

pkg/models/relationships.go

@@ -138,6 +138,19 @@ func (r *RelatedMovies) Add(movies ...MoviesScenes) {
 	r.list = append(r.list, movies...)
 }
 
+// ForID returns the MoviesScenes object for the given movie ID. Returns nil if not found.
+func (r *RelatedMovies) ForID(id int) *MoviesScenes {
+	r.mustLoaded()
+
+	for _, v := range r.list {
+		if v.MovieID == id {
+			return &v
+		}
+	}
+
+	return nil
+}
+
 func (r *RelatedMovies) load(fn func() ([]MoviesScenes, error)) error {
 	if r.Loaded() {
 		return nil