Support setting WireMockServerSettings via Environment (#954)

* Support parsing environment variables (WireMockServerSettings__)

* case ignore

* fix

* SimpleSettingsParserTests

* .

* int

* more test

test/WireMock.Net.Tests/Extensions/DictionaryExtensionsTests.cs

@@ -0,0 +1,51 @@
+using System.Collections;
+using FluentAssertions;
+using WireMock.Extensions;
+using Xunit;
+
+namespace WireMock.Net.Tests.Extensions;
+
+public class DictionaryExtensionsTests
+{
+    [Fact]
+    public void TryGetStringValue_WhenKeyExistsAndValueIsString_ReturnsTrueAndStringValue()
+    {
+        // Arrange
+        var dictionary = new Hashtable { { "key", "value" } };
+
+        // Act
+        var result = dictionary.TryGetStringValue("key", out var value);
+
+        // Assert
+        result.Should().BeTrue();
+        value.Should().Be("value");
+    }
+
+    [Fact]
+    public void TryGetStringValue_WhenKeyExistsAndValueIsNotString_ReturnsTrueAndStringValue()
+    {
+        // Arrange
+        var dictionary = new Hashtable { { "key", 123 } };
+
+        // Act
+        var result = dictionary.TryGetStringValue("key", out var value);
+
+        // Assert
+        result.Should().BeTrue();
+        value.Should().Be("123");
+    }
+
+    [Fact]
+    public void TryGetStringValue_WhenKeyDoesNotExist_ReturnsFalseAndNull()
+    {
+        // Arrange
+        var dictionary = new Hashtable { { "otherKey", "value" } };
+
+        // Act
+        var result = dictionary.TryGetStringValue("key", out var value);
+
+        // Assert
+        result.Should().BeFalse();
+        value.Should().BeNull();
+    }
+}