Enables code execution within a Docker sandbox

Adds a Docker-based execution sandbox to enhance the security and resource management of code execution.

This change introduces:
- New execution services for C#, C++, Java, Kotlin, and Python that utilize the sandbox.
- Configuration options for enabling/disabling the sandbox and specifying Docker images for different languages.
- Batch execution support for C++ to improve the efficiency of generating answer files.
- Docker CLI installation in the worker's Dockerfile.

The sandbox provides improved isolation and resource control during code execution, preventing potential security vulnerabilities and resource exhaustion.

tests/LiquidCode.Tester.Worker.Tests/ExecutionServiceFactoryTests.cs

@@ -1,4 +1,5 @@
 using LiquidCode.Tester.Worker.Services;
+using LiquidCode.Tester.Worker.Services.Sandbox;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
@@ -32,6 +33,7 @@ public class ExecutionServiceFactoryTests
         services.AddSingleton<KotlinExecutionService>();
         services.AddSingleton<CSharpExecutionService>();
         services.AddSingleton<PythonExecutionService>();
+    services.AddSingleton<IExecutionSandbox>(_ => Mock.Of<IExecutionSandbox>());
 
         _serviceProvider = services.BuildServiceProvider();
         _factory = new ExecutionServiceFactory(