Fix file deletion

CHDataManagement/Model/Content.swift

@@ -123,6 +123,22 @@ final class Content: ObservableObject {
 
     func remove(_ file: FileResource) {
         files.remove(file)
-        #warning("Remove file from required files, thumbnails, post images, etc.")
+        for post in posts {
+            post.remove(file)
+        }
+
+        for page in pages {
+            page.remove(file)
+        }
+
+        for tag in tags {
+            tag.remove(file)
+        }
+        settings.remove(file)
+        #warning("Remove MainView.selectedFile when deleting file")
+    }
+
+    func file(withOutputPath: String) -> FileResource? {
+        files.first { $0.absoluteUrl == withOutputPath }
     }
 }