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/HttpException.cs

@@ -0,0 +1,105 @@
+using System;
+using System.Net;
+
+namespace EmbedIO
+{
+    /// <summary>
+    /// When thrown, breaks the request handling control flow
+    /// and sends an error response to the client.
+    /// </summary>
+#pragma warning disable CA1032 // Implement standard exception constructors - they have no meaning here.
+    public partial class HttpException : Exception, IHttpException
+#pragma warning restore CA1032
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="HttpException"/> class,
+        /// with no message to include in the response.
+        /// </summary>
+        /// <param name="statusCode">The status code to set on the response.</param>
+        public HttpException(int statusCode)
+        {
+            StatusCode = statusCode;
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="HttpException"/> class,
+        /// with no message to include in the response.
+        /// </summary>
+        /// <param name="statusCode">The status code to set on the response.</param>
+        public HttpException(HttpStatusCode statusCode)
+            : this((int)statusCode)
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="HttpException"/> class,
+        /// with a message to include in the response.
+        /// </summary>
+        /// <param name="statusCode">The status code to set on the response.</param>
+        /// <param name="message">A message to include in the response as plain text.</param>
+        public HttpException(int statusCode, string? message)
+            : base(message)
+        {
+            StatusCode = statusCode;
+            HttpExceptionMessage = message;
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="HttpException"/> class,
+        /// with a message to include in the response.
+        /// </summary>
+        /// <param name="statusCode">The status code to set on the response.</param>
+        /// <param name="message">A message to include in the response as plain text.</param>
+        public HttpException(HttpStatusCode statusCode, string? message)
+            : this((int)statusCode, message)
+        {
+        }
+        
+        /// <summary>
+        /// Initializes a new instance of the <see cref="HttpException" /> class,
+        /// with a message and a data object to include in the response.
+        /// </summary>
+        /// <param name="statusCode">The status code to set on the response.</param>
+        /// <param name="message">A message to include in the response as plain text.</param>
+        /// <param name="data">The data object to include in the response.</param>
+        public HttpException(int statusCode, string? message, object? data)
+            : this(statusCode, message)
+        {
+            DataObject = data;
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="HttpException" /> class,
+        /// with a message and a data object to include in the response.
+        /// </summary>
+        /// <param name="statusCode">The status code to set on the response.</param>
+        /// <param name="message">A message to include in the response as plain text.</param>
+        /// <param name="data">The data object to include in the response.</param>
+        public HttpException(HttpStatusCode statusCode, string? message, object? data)
+            : this((int)statusCode, message, data)
+        {
+        }
+
+        /// <inheritdoc />
+        public int StatusCode { get; }
+ 
+        /// <inheritdoc />
+        public object? DataObject { get; }
+
+        /// <inheritdoc />
+        string? IHttpException.Message => HttpExceptionMessage;
+
+        // This property is necessary because when an exception with a null Message is thrown
+        // the CLR provides a standard message. We want null to remain null in IHttpException.
+        private string? HttpExceptionMessage { get; }
+
+        /// <inheritdoc />
+        /// <remarks>
+        /// <para>This method does nothing; there is no need to call
+        /// <c>base.PrepareResponse</c> in overrides of this method.</para>
+        /// </remarks>
+        public virtual void PrepareResponse(IHttpContext context)
+        {
+        }
+    }
+}