This change updates the Automation plugin to make use of the `use_new_show_route` plugin flag, as well as generally updating the UI to match current admin UI guidelines. Notable changes include:
- Moving template/router/controller files to make use of the `admin.adminPlugins.show` route.
- Changing the URIs from `/admin/plugins/discourse-automation` to `/admin/plugins/automation`, to match the `PLUGIN_NAME`.
- Adding UI wrappers around the New/Edit forms, and polishing the list of defined automations.
A previous refactor has prevented errors to show correctly. The guilt of the issue is that we were not calling the error variable correctly in the templates.
This commit also adds a spec for this case, and removes the need for `I18n.backend.store_translations` in specs so we don't have to write too much boilerplate each time we write a spec.
