- https://community.openproject.org/work_packages/57816
- added form for item creation
- added borderbox in items component

- render hierarchical item in component
- add missing routes
- localize dry-validation error

- removing ineffective system arguments
- add i18n support for validation messages

The `LocaleExtractor` recognizes these kind of files:

  - `<locale>.yaml`
  - `<locale>_something.yaml`

It does not recognize these files we use:

  - `js-<locale>.yaml` (locale is extracted as `js-<locale>`)
  - `<locale>.seeders.yaml` (locale is extracted as `<locale>.seeders`)

It's fixed by deleting the `js-` prefix and the `.seeders` suffix from
the extracted locale.