Show current user rank in leaderboard (#1263)

close #1000 maybe #1178 too

*  Show current user rank in the leaderboard with +-1 user (only on leaderboard 
*  Extend auto_main script to use random user.
*  Support colSpan in the DataTable component (I haven't verified colSpan in header yet, leave that until we need it)
*  Refactor OasstError to include the path and request method.

website/src/pages/api/leaderboard.ts

@@ -1,5 +1,6 @@
 import { withoutRole } from "src/lib/auth";
 import { createApiClient } from "src/lib/oasst_client_factory";
+import { getBackendUserCore } from "src/lib/users";
 import { LeaderboardTimeFrame } from "src/types/Leaderboard";
 
 /**
@@ -7,9 +8,29 @@ import { LeaderboardTimeFrame } from "src/types/Leaderboard";
  */
 const handler = withoutRole("banned", async (req, res, token) => {
   const oasstApiClient = await createApiClient(token);
+  const backendUser = await getBackendUserCore(token.sub);
   const time_frame = (req.query.time_frame as LeaderboardTimeFrame) ?? LeaderboardTimeFrame.day;
-  const info = await oasstApiClient.fetch_leaderboard(time_frame, { limit: req.query.limit as unknown as number });
-  res.status(200).json(info);
+  const includeUserStats = req.query.includeUserStats;
+
+  if (includeUserStats !== "true") {
+    const leaderboard = await oasstApiClient.fetch_leaderboard(time_frame, {
+      limit: req.query.limit as unknown as number,
+    });
+    return res.status(200).json(leaderboard);
+  }
+  const user = await oasstApiClient.fetch_frontend_user(backendUser);
+
+  const [leaderboard, user_stats] = await Promise.all([
+    oasstApiClient.fetch_leaderboard(time_frame, {
+      limit: req.query.limit as unknown as number,
+    }),
+    oasstApiClient.fetch_user_stats_window(user.user_id, time_frame, 3),
+  ]);
+
+  res.status(200).json({
+    ...leaderboard,
+    user_stats_window: user_stats.leaderboard.map((stats) => ({ ...stats, is_window: true })),
+  });
 });
 
 export default handler;