BUG: Map is currently hardcoded for all events

## 🐛 Bug Report

### What went wrong? 🤔

All events, on the participant dashboard, have a map hardcoded. This should be instead customizable by the event organizer

### Expected Behavior

The map should be customizable for each event and shouldn't affect other events

### Actual Behavior

Currently, it is hardcoded, and when the user tries to upload a map, the upload fails because it is not declared in the graphql inputs schema

### Steps to Reproduce Issue
Login as a participant to an event and click on the map tab to see the hardcoded map

Start at the participant dashboard's map tab and trace how the map is selected for an event. Then inspect the GraphQL inputs schema and the map upload flow. Done means each event can upload and display its own customizable map without changing other events, and the upload succeeds through the schema.

Scritto dal modello di indicizzazione a partire dal testo della issue.