Improve page and post detail views

CHDataManagement/Model/LocalizedPage.swift

@@ -56,7 +56,7 @@ final class LocalizedPage: ObservableObject {
     var requiredFiles: Set<String> = []
 
     @Published
-    var linkPreviewImage: String?
+    var linkPreviewImage: ImageResource?
 
     @Published
     var linkPreviewTitle: String?
@@ -71,7 +71,7 @@ final class LocalizedPage: ObservableObject {
          files: Set<String> = [],
          externalFiles: Set<String> = [],
          requiredFiles: Set<String> = [],
-         linkPreviewImage: String? = nil,
+         linkPreviewImage: ImageResource? = nil,
          linkPreviewTitle: String? = nil,
          linkPreviewDescription: String? = nil) {
         self.urlString = urlString