Configure Kestrel endpoint and hosting options in settings

Added "UseWindowsService" and "UseKestrelConfig" flags to appsettings.json. Defined a custom Kestrel HTTP endpoint at http://localhost:1111 to control how the application is hosted and served.

EnvelopeGenerator.ServiceHost/appsettings.json

@@ -12,5 +12,14 @@
   "SupportedCultures": [ "de-DE", "en-US" ],
   "ConnectionStrings": {
     "Default": "Server=SDD-VMP04-SQL17\\DD_DEVELOP01;Database=DD_ECM;User Id=sa;Password=dd;Encrypt=false;TrustServerCertificate=True;"
+  },
+  "UseWindowsService": false,
+  "UseKestrelConfig": false,
+  "Kestrel": {
+    "Endpoints": {
+      "Http": {
+        "Url": "http://localhost:1111"
+      }
+    }
   }
 }