Prevent saving when some file properties change

CHDataManagement/Model/FileResource.swift

@@ -48,12 +48,22 @@ final class FileResource: Item, LocalizedItem {
     var isAsset: Bool
 
     /// The dimensions of the image
-    @Published
-    var imageDimensions: CGSize? = nil
+    var imageDimensions: CGSize? {
+        get { content.dimensions(of: id) }
+        set {
+            content.cache(dimensions: newValue, of: id)
+            didChange(save: false)
+        }
+    }
 
     /// The size of the file in bytes
-    @Published
-    var fileSize: Int? = nil
+    var fileSize: Int? {
+        get { content.size(of: id) }
+        set {
+            content.cache(size: newValue, of: id)
+            didChange(save: false)
+        }
+    }
 
     var savedData: Data?