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

ui/v2.5/src/utils/image.tsx

@@ -53,8 +53,22 @@ const usePasteImage = (
   return false;
 };
 
+const imageToDataURL = async (url: string) => {
+  const response = await fetch(url);
+  const blob = await response.blob();
+  return new Promise<string>((resolve, reject) => {
+    const reader = new FileReader();
+    reader.onloadend = () => {
+      resolve(reader.result as string);
+    };
+    reader.onerror = reject;
+    reader.readAsDataURL(blob);
+  });
+};
+
 const Image = {
   onImageChange,
   usePasteImage,
+  imageToDataURL,
 };
 export default Image;