Create WireMock.Net.MimePart project (#1300)

* Create WireMock.Net.MimePart project

* .

* REFACTOR

* ILRepack

* --

* ...

* x

* x

* .

* fix

* public class MimePartMatcher

* shared

* min

* .

* <!--<DelaySign>true</DelaySign>-->

* Update README.md

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

src/WireMock.Net.Minimal/ResponseBuilders/Response.WithCallback.cs

@@ -0,0 +1,64 @@
+// Copyright © WireMock.Net
+
+using System;
+using System.Diagnostics.CodeAnalysis;
+using System.Threading.Tasks;
+using Stef.Validation;
+
+namespace WireMock.ResponseBuilders;
+
+public partial class Response
+{
+    /// <summary>
+    /// A delegate to execute to generate the response.
+    /// </summary>
+    [MemberNotNullWhen(true, nameof(WithCallbackUsed))]
+    public Func<IRequestMessage, ResponseMessage>? Callback { get; private set; }
+
+    /// <summary>
+    /// A delegate to execute to generate the response async.
+    /// </summary>
+    [MemberNotNullWhen(true, nameof(WithCallbackUsed))]
+    public Func<IRequestMessage, Task<ResponseMessage>>? CallbackAsync { get; private set; }
+
+    /// <summary>
+    /// Defines if the method WithCallback(...) is used.
+    /// </summary>
+    public bool WithCallbackUsed { get; private set; }
+
+    /// <inheritdoc />
+    public IResponseBuilder WithCallback(Func<IRequestMessage, ResponseMessage> callbackHandler)
+    {
+        Guard.NotNull(callbackHandler);
+
+        return WithCallbackInternal(true, callbackHandler);
+    }
+
+    /// <inheritdoc />
+    public IResponseBuilder WithCallback(Func<IRequestMessage, Task<ResponseMessage>> callbackHandler)
+    {
+        Guard.NotNull(callbackHandler);
+
+        return WithCallbackInternal(true, callbackHandler);
+    }
+
+    private IResponseBuilder WithCallbackInternal(bool withCallbackUsed, Func<IRequestMessage, ResponseMessage> callbackHandler)
+    {
+        Guard.NotNull(callbackHandler);
+
+        WithCallbackUsed = withCallbackUsed;
+        Callback = callbackHandler;
+
+        return this;
+    }
+
+    private IResponseBuilder WithCallbackInternal(bool withCallbackUsed, Func<IRequestMessage, Task<ResponseMessage>> callbackHandler)
+    {
+        Guard.NotNull(callbackHandler);
+
+        WithCallbackUsed = withCallbackUsed;
+        CallbackAsync = callbackHandler;
+
+        return this;
+    }
+}