Implement InMemory Transport Layer for StellaOps Router

- Added InMemoryTransportOptions class for configuration settings including timeouts and latency.
- Developed InMemoryTransportServer class to handle connections, frame processing, and event management.
- Created ServiceCollectionExtensions for easy registration of InMemory transport services.
- Established project structure and dependencies for InMemory transport library.
- Implemented comprehensive unit tests for endpoint discovery, connection management, request/response flow, and streaming capabilities.
- Ensured proper handling of cancellation, heartbeat, and hello frames within the transport layer.

tests/StellaOps.Router.Common.Tests/FrameTypeTests.cs

@@ -1,4 +1,4 @@
-using StellaOps.Router.Common;
+using StellaOps.Router.Common.Enums;
 using Xunit;
 
 namespace StellaOps.Router.Common.Tests;
@@ -19,10 +19,10 @@ public class FrameTypeTests
     [Fact]
     public void TransportType_HasExpectedValues()
     {
-        // Verify all expected transport types exist
+        // Verify all expected transport types exist (no HTTP per spec)
         Assert.True(Enum.IsDefined(typeof(TransportType), TransportType.InMemory));
         Assert.True(Enum.IsDefined(typeof(TransportType), TransportType.Tcp));
-        Assert.True(Enum.IsDefined(typeof(TransportType), TransportType.Tls));
+        Assert.True(Enum.IsDefined(typeof(TransportType), TransportType.Certificate));
         Assert.True(Enum.IsDefined(typeof(TransportType), TransportType.Udp));
         Assert.True(Enum.IsDefined(typeof(TransportType), TransportType.RabbitMq));
     }