Export participants to different formats

* CSV
* PDF (requires Python dependency `weasyprint`)
* ODS (requires Python dependency `pyexcel_ods3`)

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

js/src/graphql/config.ts

@@ -175,3 +175,13 @@ export const WEB_PUSH = gql`
     }
   }
 `;
+
+export const EVENT_PARTICIPANTS = gql`
+  query EventParticipants {
+    config {
+      exportFormats {
+        eventParticipants
+      }
+    }
+  }
+`;