Simplify columns in Grant Admin change list view

[estyxx]

Reduce the number of columns displayed in the Grant admin change list view. Specifically, remove the individual amount fields ("ticket_amount", "travel_amount", "accommodation_amount") in favor of keeping only "total_amount". Additionally, eliminate the "applicant_reply_sent_at" and "applicant_reply_deadline" fields from both the display and the model, as this information is already handled by the email system (via the SentEmail model).