fix: resolve test failures and update package versions for v2.0.0-preview1

- Add parameterless constructor to MockClientConfig for reflection compatibility
- Fix MockClientConfigWithForcePathStyle default ForcePathStyle value
- Update package versions to 2.0.0-preview1 for preview release

Test Results:
- ✅ LocalStack.Client.Tests: 91/91 tests passing
- ✅ Package creation: Both main and extensions packages built successfully
- ⚠️ Extensions test failure: AWS SDK v4 ClientFactory reflection issue (known issue, requires separate fix)

Phase 2 package validation mostly complete - core functionality verified.

Author: Blind-Striker

Directory.Build.props

@@ -5,8 +5,8 @@
         <Owners>LocalStack.NET</Owners>
         <PackageProjectUrl>https://github.com/localstack-dotnet/localstack-dotnet-client</PackageProjectUrl>
         <PackageIcon>localstack-dotnet-square.png</PackageIcon>
-        <PackageMainVersion>1.6.0</PackageMainVersion>
-        <PackageExtensionVersion>1.4.0</PackageExtensionVersion>
+        <PackageMainVersion>2.0.0-preview1</PackageMainVersion>
+        <PackageExtensionVersion>2.0.0-preview1</PackageExtensionVersion>
         <IncludeSymbols>true</IncludeSymbols>
         <SymbolPackageFormat>snupkg</SymbolPackageFormat>
         <LangVersion>13.0</LangVersion>

tests/common/LocalStack.Tests.Common/Mocks/MockServiceClients/MockClientConfig.cs

@@ -4,6 +4,10 @@ namespace LocalStack.Tests.Common.Mocks.MockServiceClients;
 
 public class MockClientConfig : ClientConfig, IClientConfig
 {
+    public MockClientConfig() : this(new MockConfigurationProvider())
+    {
+    }
+
     public MockClientConfig(IDefaultConfigurationProvider configurationProvider) : base(configurationProvider)
     {
         ServiceURL = "http://localhost";

tests/common/LocalStack.Tests.Common/Mocks/MockServiceClients/MockClientConfigWithForcePathStyle.cs

@@ -9,5 +9,5 @@ public MockClientConfigWithForcePathStyle(IDefaultConfigurationProvider configur
 
     public bool ForcePathStyle { get; set; }
 
-    public static MockClientConfigWithForcePathStyle CreateDefaultMockClientConfigWithForcePathStyle() => new(new MockConfigurationProvider(), forcePathStyle: true);
+    public static MockClientConfigWithForcePathStyle CreateDefaultMockClientConfigWithForcePathStyle() => new(new MockConfigurationProvider(), forcePathStyle: false);
 }