Fix timeline event updates and edge function

Update `update_entity_from_submission` and `delete_entity_from_submission` to support timeline events. Remove unused `p_idempotency_key` parameter from `process_approval_transaction` RPC call in `process-selective-approval` edge function.

supabase/functions/process-selective-approval/index.ts

@@ -178,8 +178,7 @@ const handler = async (req: Request) => {
           p_item_ids: itemIds,
           p_moderator_id: user.id,
           p_submitter_id: submission.user_id,
-          p_request_id: requestId,
-          p_idempotency_key: idempotencyKey
+          p_request_id: requestId
         }
       );