Bump node-forge and @vue/cli-service in /demo-site

Bumps [node-forge](https://github.com/digitalbazaar/forge) to 1.3.1 and updates ancestor dependency [@vue/cli-service](https://github.com/vuejs/vue-cli/tree/HEAD/packages/@vue/cli-service). These dependencies need to be updated together.


Updates `node-forge` from 0.10.0 to 1.3.1
- [Release notes](https://github.com/digitalbazaar/forge/releases)
- [Changelog](https://github.com/digitalbazaar/forge/blob/main/CHANGELOG.md)
- [Commits](digitalbazaar/forge@0.10.0...v1.3.1)

Updates `@vue/cli-service` from 4.4.1 to 5.0.8
- [Release notes](https://github.com/vuejs/vue-cli/releases)
- [Changelog](https://github.com/vuejs/vue-cli/blob/dev/CHANGELOG.md)
- [Commits](https://github.com/vuejs/vue-cli/commits/v5.0.8/packages/@vue/cli-service)

---
updated-dependencies:
- dependency-name: node-forge
  dependency-type: indirect
- dependency-name: "@vue/cli-service"
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>