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/ExceptionHandlerCallback.cs

@@ -0,0 +1,22 @@
+using System;
+using System.Net;
+using System.Threading.Tasks;
+
+namespace EmbedIO
+{
+    /// <summary>
+    /// A callback used to provide information about an unhandled exception occurred while processing a request.
+    /// </summary>
+    /// <param name="context">An <see cref="IHttpContext" /> interface representing the context of the request.</param>
+    /// <param name="exception">The unhandled exception.</param>
+    /// <returns>A <see cref="Task" /> representing the ongoing operation.</returns>
+    /// <remarks>
+    /// <para>When this delegate is called, the response's status code has already been set to
+    /// <see cref="HttpStatusCode.InternalServerError" />.</para>
+    /// <para>Any exception thrown by a handler (even a HTTP exception) will go unhandled: the web server
+    /// will not crash, but processing of the request will be aborted, and the response will be flushed as-is.
+    /// In other words, it is not a good ides to <c>throw HttpException.NotFound()</c> (or similar)
+    /// from a handler.</para>
+    /// </remarks>
+    public delegate Task ExceptionHandlerCallback(IHttpContext context, Exception exception);
+}