Changed enums to string

String is easyer to decode and the sendable data in the frontend will be
limited.

backend/src/handlers/ticket.rs

@@ -24,7 +24,7 @@ pub async fn create_ticket(
     .bind(body.category.to_string())
     .bind(body.description.to_string())
     .bind(body.betreff.to_string())
-    .bind(body.room.to_string())
+    .bind(body.room)
     .execute(&data.db)
     .await;