refactor(di): unify Application and Infrastructure DI registrations under a central method

- Added central AddEnvelopeGenerator extension to aggregate existing DI setups
- Introduced EGConfiguration for modular service registration
- Standardized configuration pattern for Application and Infrastructure layers
- Simplified distributed cache and localization registration

EnvelopeGenerator.Finalizer/Program.cs

@@ -28,7 +28,7 @@ try
         ?? throw new InvalidOperationException($"Connection string '{cnnStrName}' is missing in the application configuration.");
 
     #pragma warning disable CS0618 // Type or member is obsolete
-    builder.Services.AddEnvelopeGeneratorInfrastructureServices(
+    builder.Services.AddEGInfrastructureServices(
         opt =>
         {
             opt.AddDbTriggerParams(config);