Add Canonical JSON serialization library with tests and documentation

- Implemented CanonJson class for deterministic JSON serialization and hashing.
- Added unit tests for CanonJson functionality, covering various scenarios including key sorting, handling of nested objects, arrays, and special characters.
- Created project files for the Canonical JSON library and its tests, including necessary package references.
- Added README.md for library usage and API reference.
- Introduced RabbitMqIntegrationFactAttribute for conditional RabbitMQ integration tests.

examples/router/tests/Examples.Integration.Tests/GatewayFixture.cs

@@ -3,6 +3,7 @@ using Examples.Inventory.Microservice.Endpoints;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Mvc.Testing;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Hosting;
 using StellaOps.Microservice;
 using StellaOps.Router.Common.Enums;
@@ -17,6 +18,7 @@ namespace Examples.Integration.Tests;
 /// </summary>
 public sealed class GatewayFixture : IAsyncLifetime
 {
+    private readonly InMemoryConnectionRegistry _registry = new();
     private WebApplicationFactory<Examples.Gateway.Program>? _gatewayFactory;
     private IHost? _billingHost;
     private IHost? _inventoryHost;
@@ -32,7 +34,8 @@ public sealed class GatewayFixture : IAsyncLifetime
                 builder.UseEnvironment("Testing");
                 builder.ConfigureServices(services =>
                 {
-                    services.AddInMemoryTransport();
+                    services.RemoveAll<InMemoryConnectionRegistry>();
+                    services.AddSingleton(_registry);
                 });
             });
 
@@ -59,7 +62,8 @@ public sealed class GatewayFixture : IAsyncLifetime
         billingBuilder.Services.AddScoped<CreateInvoiceEndpoint>();
         billingBuilder.Services.AddScoped<GetInvoiceEndpoint>();
         billingBuilder.Services.AddScoped<UploadAttachmentEndpoint>();
-        billingBuilder.Services.AddInMemoryTransport();
+        billingBuilder.Services.AddSingleton(_registry);
+        billingBuilder.Services.AddInMemoryTransportClient();
 
         _billingHost = billingBuilder.Build();
         await _billingHost.StartAsync();
@@ -84,7 +88,8 @@ public sealed class GatewayFixture : IAsyncLifetime
         });
         inventoryBuilder.Services.AddScoped<ListItemsEndpoint>();
         inventoryBuilder.Services.AddScoped<GetItemEndpoint>();
-        inventoryBuilder.Services.AddInMemoryTransport();
+        inventoryBuilder.Services.AddSingleton(_registry);
+        inventoryBuilder.Services.AddInMemoryTransportClient();
 
         _inventoryHost = inventoryBuilder.Build();
         await _inventoryHost.StartAsync();