Add video tutorial for multisig, improve explorer statistics page (#4708)

- **fix(app2): add host**
- **feat(multisig): add video tutorial**
- **fix(app2): refine design**
- **refactor(app2): clean up video tutorial**
- **feat(app2): more data in charts**
- **feat(app2): daily packets chart**
- **feat(app2): synchornize hover states**
- **feat(app2): dual chart layout**