Add image aspect ratio to prevent page jumps

CHDataManagement/Model/FileResource.swift

@@ -152,11 +152,22 @@ final class FileResource: Item, LocalizedItem {
     }
 
     func determineImageDimensions() {
-        let size = getImageDimensions()
+        let size = getCurrentImageDimensions()
         self.update(imageDimensions: size)
     }
 
-    private func getImageDimensions() -> CGSize? {
+    func getImageDimensions() -> CGSize? {
+        if let imageDimensions {
+            return imageDimensions
+        }
+        guard let size = getCurrentImageDimensions() else {
+            return nil
+        }
+        self.update(imageDimensions: size)
+        return size
+    }
+
+    private func getCurrentImageDimensions() -> CGSize? {
         guard type.isImage else {
             return nil
         }