Refactor project structure and improve security

- Updated `.gitignore` to exclude `FodyWeavers.xsd`.
- Added or modified `/EnvelopeGenerator.Server/tekh_softHSM_test.md`.
- Added or modified `/EnvelopeGenerator.Server/publish-output`.
- Added or modified `/legacy/App`.
- Moved `appsettings.Secrets.json` to `/src/presentation/`.
- Removed sensitive configuration data from `appsettings.Secrets.json`, including RabbitMQ credentials and email account settings.
- Improved security by removing hardcoded secrets and restructuring configuration files.

src/presentation/DigitalData.MessagingService.API/appsettings.Secrets.json

@@ -1,32 +0,0 @@
-{
-  "AllowedHosts": "*",
-  "RabbitMQ": {
-    "HostName": "172.24.12.56",
-    "Port": 5672,
-    "UserName": "admin",
-    "Password": "fl!'D}4;pYBb\\VD&{6]]G*\\0Bq8fVIn0j?Sgm\\2A,6GS47g5Dj",
-    "VirtualHost": "/",
-    "AutomaticRecoveryEnabled": true,
-    "NetworkRecoveryIntervalSeconds": 10,
-    "QueueName": "emailprofiler.email.outbox",
-    "ExchangeName": "emailprofiler.emails",
-    "RoutingKey": "email.outbox",
-    "DlqQueueName": "emailprofiler.email.outbox.dlq",
-    "DlqExchangeName": "emailprofiler.emails.dlq",
-    "DlqRoutingKey": "email.outbox.dlq"
-  },
-  "EmailAccounts": {
-    "Accounts": [
-      {
-        "Id": "1",
-        "Username": "test-flow@digitaldata.works",
-        "Password": "ddemail108",
-        "PasswordEncrypted": false,
-        "SmtpServer": "kundencenter.triplew.de",
-        "SmtpPort": 465,
-        "SmtpUseSsl": true,
-        "UseOAuth2": false
-      }
-    ]
-  }
-}