Bump ms, express, compression and serve-index in /client

Bumps [ms](https://github.com/vercel/ms) to 2.0.0 and updates ancestor dependencies [ms](https://github.com/vercel/ms), [express](https://github.com/expressjs/express), [compression](https://github.com/expressjs/compression) and [serve-index](https://github.com/expressjs/serve-index). These dependencies need to be updated together.


Updates `ms` from 0.7.1 to 2.0.0
- [Release notes](https://github.com/vercel/ms/releases)
- [Commits](vercel/ms@0.7.1...2.0.0)

Updates `express` from 4.13.4 to 4.18.2
- [Release notes](https://github.com/expressjs/express/releases)
- [Changelog](https://github.com/expressjs/express/blob/master/History.md)
- [Commits](expressjs/express@4.13.4...4.18.2)

Updates `compression` from 1.6.1 to 1.7.4
- [Release notes](https://github.com/expressjs/compression/releases)
- [Changelog](https://github.com/expressjs/compression/blob/master/HISTORY.md)
- [Commits](expressjs/compression@1.6.1...1.7.4)

Updates `serve-index` from 1.7.3 to 1.9.1
- [Release notes](https://github.com/expressjs/serve-index/releases)
- [Changelog](https://github.com/expressjs/serve-index/blob/master/HISTORY.md)
- [Commits](expressjs/serve-index@v1.7.3...v1.9.1)

---
updated-dependencies:
- dependency-name: ms
  dependency-type: indirect
- dependency-name: express
  dependency-type: direct:development
- dependency-name: compression
  dependency-type: indirect
- dependency-name: serve-index
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>