refactor: Umbenennung von GTX in Gtx und GTXMessagingConfig in SmsParams

EnvelopeGenerator.Application/Configurations/GTXMessagingConfig.cs

@@ -1,7 +0,0 @@
-namespace EnvelopeGenerator.Application.Configurations
-{
-    public class GTXMessagingConfig
-    {
-        public required string AuthKey { get; init; }
-    }
-}

EnvelopeGenerator.Application/Configurations/GtxMessaging/SmsParams.cs

@@ -0,0 +1,7 @@
+namespace EnvelopeGenerator.Application.Configurations.GtxMessaging
+{
+    public class SmsParams
+    {
+        public required string AuthKey { get; init; }
+    }
+}