Got at least one data fetching method working; turns out, we can't use a patched LogicStack to get the data

Vendor/EmbedIO-3.5.2/Files/Internal/Base64Utility.cs

@@ -0,0 +1,12 @@
+using System;
+
+namespace EmbedIO.Files.Internal
+{
+    internal static class Base64Utility
+    {
+        // long is 8 bytes
+        // base64 of 8 bytes is 12 chars, but the last one is padding
+        public static string LongToBase64(long value)
+            => Convert.ToBase64String(BitConverter.GetBytes(value)).Substring(0, 11);
+    }
+}