Add Grpc ProtoBuf support (request-response) (#1047)

* ProtoBuf

* .

* x

* ---

* x

* fx

* ...

* sc

* ...

* .

* groen

* x

* fix tests

* ok!?

* fix tests

* fix tests

* !

* x

* 6

* .

* x

* ivaluematcher

* transformer

* .

* sc

* .

* mapping

* x

* tra

* com

* ...

* .

* .

* .

* AddProtoDefinition

* .

* set

* grpahj

* .

* .

* IdOrText

* ...

* async

* async2

* .

* t

* nuget

* <PackageReference Include="ProtoBufJsonConverter" Version="0.2.0-preview-04" />

* http version

* tests

* .WithHttpVersion("2")

* <PackageReference Include="ProtoBufJsonConverter" Version="0.2.0" />

* HttpVersionParser

src/WireMock.Net.Abstractions/Admin/Mappings/MappingModel.cs

@@ -98,4 +98,9 @@ public class MappingModel
     /// The probability when this request should be matched. Value is between 0 and 1. [Optional]
     /// </summary>
     public double? Probability { get; set; }
+
+    /// <summary>
+    /// The Grpc ProtoDefinition which is used for this mapping (request and response). [Optional]
+    /// </summary>
+    public string? ProtoDefinition { get; set; }
 }