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/Imports/Import.cs

@@ -0,0 +1,39 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace Wasmtime.Imports
+{
+    /// <summary>
+    /// The base class for import types.
+    /// </summary>
+    public abstract class Import
+    {
+        internal Import(IntPtr importType)
+        {
+            unsafe
+            {
+                var moduleName = Interop.wasm_importtype_module(importType);
+                ModuleName = Marshal.PtrToStringUTF8((IntPtr)moduleName->data, (int)moduleName->size);
+
+                var name = Interop.wasm_importtype_name(importType);
+                Name = Marshal.PtrToStringUTF8((IntPtr)name->data, (int)name->size);
+            }
+        }
+
+        /// <summary>
+        /// The module name of the import.
+        /// </summary>
+        public string ModuleName { get; private set; }
+
+        /// <summary>
+        /// The name of the import.
+        /// </summary>
+        public string Name { get; private set; }
+
+        /// <inheritdoc/>
+        public override string ToString()
+        {
+            return $"{ModuleName}{(string.IsNullOrEmpty(ModuleName) ? "" : ".")}{Name}";
+        }
+    }
+}