Fixed QueryStringParser for UrlEncoded values (#911)

src/WireMock.Net/Util/QueryStringParser.cs

@@ -32,7 +32,7 @@ internal static class QueryStringParser
         {
             if (part.Length == 2)
             {
-                nameValueCollection.Add(part[0], part[1]);
+                nameValueCollection.Add(part[0], WebUtility.UrlDecode(part[1]));
             }
         }
 

test/WireMock.Net.Tests/Util/QueryStringParserTests.cs

@@ -38,6 +38,21 @@ public class QueryStringParserTests
         actual.Should().BeEquivalentTo(expectedOutput);
     }
 
+    [Fact]
+    public void TryParse_Should_Parse_QueryStringWithUrlEncodedValues()
+    {
+        // Arrange
+        var key = "x";
+        var value = "rNaCP7hv8UOmS%2FJcujdvLw%3D%3D";
+
+        // Act
+        var result = QueryStringParser.TryParse($"{key}={value}", true, out var actual);
+
+        // Assert
+        result.Should().BeTrue();
+        actual.Should().BeEquivalentTo(new Dictionary<string, string> { { "x", "rNaCP7hv8UOmS/JcujdvLw==" } });
+    }
+
     [Fact]
     public void Parse_WithNullString()
     {