Improve UI of empty Explore and Category pages.

lib/components/loading.dart

@@ -6,6 +6,7 @@ class NetworkError extends StatelessWidget {
     required this.message,
     this.retry,
     this.withAppbar = true,
+    this.buttonText,
   });
 
   final String message;
@@ -14,6 +15,8 @@ class NetworkError extends StatelessWidget {
 
   final bool withAppbar;
 
+  final String? buttonText;
+
   @override
   Widget build(BuildContext context) {
     var cfe = CloudflareException.fromString(message);
@@ -60,7 +63,7 @@ class NetworkError extends StatelessWidget {
             else
               FilledButton(
                 onPressed: retry,
-                child: Text('Retry'.tl),
+                child: Text(buttonText ?? 'Retry'.tl),
               ),
         ],
       ),