This child bounty is for OpenSquare's retroactive work to migrate statescan v1 to v2. The work includes:

1. Abandon next.js and SSO, and rewrite the fronted code with react. We redesigned most UI components and implemented dark mode. The new code is also more friendly and modularized to support common substrate chains.
2. We rewrite most scan scripts for uniques/assets pallet, and improve the logic toe scan on-chain accounts.
3. NFT parsing scripts are refactored into several modules, so it will become easier to fetch and parse thousands of NFT resources including images and videos.
4. Create a common package to extract code handling with mongodb.
5. Extract calls from extrinsics and show them in separated list and detail pages.