Sort file lists for consistent storage

CHDataManagement/Import/Importer.swift

@@ -219,9 +219,9 @@ final class Importer {
             }
             let page = LocalizedPageFile(
                 url: id,
-                files: pageFiles,
-                externalFiles: externalFiles,
-                requiredFiles: requiredFiles,
+                files: pageFiles.sorted(),
+                externalFiles: externalFiles.sorted(),
+                requiredFiles: requiredFiles.sorted(),
                 title: content.title!,
                 linkPreviewImage: thumbnail?.name,
                 linkPreviewTitle: content.linkPreviewTitle,
@@ -320,7 +320,7 @@ final class Importer {
         let images = page.linkPreviewImage.map { [$0] } ?? []
 
         return LocalizedPostFile(
-            images: Set(images),
+            images: images.sorted(),
             title: page.linkPreviewTitle ?? page.title,
             content: content,
             lastModifiedDate: nil)