Move Wasmtime for .NET to the Wasmtime repo.

This moves the Wasmtime for .NET implementation to the Wasmtime repo.

Wasmtime for .NET is a binding of the Wasmtime API for use in .NET.

crates/misc/dotnet/src/WasmtimeException.cs

@@ -0,0 +1,24 @@
+using System;
+using System.Runtime.Serialization;
+
+namespace Wasmtime
+{
+    /// <summary>
+    /// The base type for Wasmtime exceptions.
+    /// </summary>
+    [System.Serializable]
+    public class WasmtimeException : Exception
+    {
+        /// <inheritdoc/>
+        public WasmtimeException() { }
+
+        /// <inheritdoc/>
+        public WasmtimeException(string message) : base(message) { }
+
+        /// <inheritdoc/>
+        public WasmtimeException(string message, Exception inner) : base(message, inner) { }
+
+        /// <inheritdoc/>
+        protected WasmtimeException(SerializationInfo info, StreamingContext context) : base(info, context) { }
+    }
+}