Add RabbitMQ support with configuration and connection

Added support for RabbitMQ integration:
- Updated project to target `net462` and `net8.0`.
- Added NuGet dependencies: `RabbitMQ.Client`, `Microsoft.Extensions.Logging.Abstractions`, and `Microsoft.Extensions.Options.ConfigurationExtensions`.
- Introduced `RabbitMqConfiguration` class for managing RabbitMQ settings.
- Implemented `RabbitMqConnectionFactory` for creating and managing RabbitMQ connections with lazy initialization, async disposal, and logging support.

src/DigitalData.MessagingService.RabbitMQ/DigitalData.MessagingService.RabbitMQ.csproj

@@ -5,7 +5,9 @@
   </PropertyGroup>
 	
   <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="10.0.10" />
     <PackageReference Include="RabbitMQ.Client" Version="7.2.1" />
+    <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="10.0.10" />
   </ItemGroup>
 	  
 </Project>

src/DigitalData.MessagingService.RabbitMQ/RabbitMqConfiguration.cs

@@ -0,0 +1,55 @@
+namespace DigitalData.MessagingService.RabbitMQ
+{
+    /// <summary>
+    /// Configuration for RabbitMQ connection
+    /// </summary>
+    public class RabbitMqConfiguration
+    {
+        /// <summary>
+        /// Configuration section name in appsettings.json
+        /// </summary>
+        public const string SectionName = "RabbitMQ";
+
+        /// <summary>
+        /// RabbitMQ server hostname
+        /// </summary>
+        public string HostName { get; set; } = "localhost";
+
+        /// <summary>
+        /// RabbitMQ AMQP port (default: 5672)
+        /// </summary>
+        public int Port { get; set; } = 5672;
+
+        /// <summary>
+        /// RabbitMQ username
+        /// </summary>
+        public string UserName { get; set; } = "guest";
+
+        /// <summary>
+        /// RabbitMQ password
+        /// </summary>
+        public string Password { get; set; } = "guest";
+
+        /// <summary>
+        /// Virtual host (default: /)
+        /// </summary>
+        public string VirtualHost { get; set; } = "/";
+
+        /// <summary>
+        /// Enable automatic recovery on connection failure
+        /// </summary>
+        public bool AutomaticRecoveryEnabled { get; set; } = true;
+
+        /// <summary>
+        /// Network recovery interval in seconds
+        /// </summary>
+        public int NetworkRecoveryIntervalSeconds { get; set; } = 10;
+
+        public string QueueName { get; set; }
+        public string ExchangeName { get; set; }
+        public string RoutingKey { get; set; }
+        public string DlqQueueName { get; set; }
+        public string DlqExchangeName { get; set; }
+        public string DlqRoutingKey { get; set; }
+    }
+}

src/DigitalData.MessagingService.RabbitMQ/RabbitMqConnectionFactory.cs

@@ -0,0 +1,82 @@
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using RabbitMQ.Client;
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace DigitalData.MessagingService.RabbitMQ
+{
+    public sealed class RabbitMqConnectionFactory : IAsyncDisposable
+    {
+        private readonly RabbitMqConfiguration _config;
+
+        private readonly ILogger<RabbitMqConnectionFactory>
+#if nullable
+?
+#endif
+            _logger;
+
+        private readonly Lazy<Task<IConnection>> _lazyConnectionProvider;
+
+        private IConnection
+#if nullable
+?
+#endif
+            _connection = null;
+
+        private CancellationToken? _cancellationToken;
+
+        public CancellationToken CancellationToken => _cancellationToken
+            ?? throw new InvalidOperationException("RabbitMqConnectionFactory is not initialized. Call InitAsync() before using this method.");
+
+        public Task<IConnection> GetConnectionAsync()
+        {
+            if (_cancellationToken != null)
+                return _lazyConnectionProvider.Value;
+            else
+                throw new InvalidOperationException("RabbitMqConnectionFactory is not initialized. Call InitAsync() before using this method.");
+        }
+
+        public RabbitMqConnectionFactory(IOptions<RabbitMqConfiguration> config)
+        {
+            _config = config.Value;
+            _lazyConnectionProvider = new Lazy<Task<IConnection>>(async () =>
+            {
+                _cancellationToken?.ThrowIfCancellationRequested();
+                var factory = new ConnectionFactory
+                {
+                    HostName = _config.HostName,
+                    Port = _config.Port,
+                    UserName = _config.UserName,
+                    Password = _config.Password,
+                    VirtualHost = _config.VirtualHost,
+                    AutomaticRecoveryEnabled = _config.AutomaticRecoveryEnabled,
+                    NetworkRecoveryInterval = TimeSpan.FromSeconds(_config.NetworkRecoveryIntervalSeconds),
+                };
+
+                _connection = await factory.CreateConnectionAsync((CancellationToken)_cancellationToken
+#if nullable
+!
+#endif
+                    );
+                return _connection;
+            });
+        }
+
+        public async Task InitAsync(CancellationToken cancellationToken = default)
+        {
+            _cancellationToken = cancellationToken;
+            _ = await GetConnectionAsync();
+        }
+
+        public async ValueTask DisposeAsync()
+        {
+            if (_connection != null)
+            {
+                await _connection.CloseAsync();
+                await _connection.DisposeAsync();
+            }
+        }
+    }
+}