npm: bump bootstrap-vue from 2.0.0-rc.11 to 2.23.1 in /frontend

Bumps [bootstrap-vue](https://github.com/bootstrap-vue/bootstrap-vue) from 2.0.0-rc.11 to 2.23.1.
- [Release notes](https://github.com/bootstrap-vue/bootstrap-vue/releases)
- [Changelog](https://github.com/bootstrap-vue/bootstrap-vue/blob/dev/CHANGELOG-OLD.md)
- [Commits](bootstrap-vue/bootstrap-vue@v2.0.0-rc.11...v2.23.1)

---
updated-dependencies:
- dependency-name: bootstrap-vue
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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