feat(17-03): register the journal-post menu item type

- Plugin implements pact.HasMenuItemTypes with a lazy app accessor
- journal-post: references by title, resolve fills the layered pattern by
  ordered replacement (id, slug, category, year, month, day) and builds the
  ordered per-locale alternates with translated slugs (x-default without
  enabled locales)
- menuitem.journal_post labels in en and pl
- TestMenuItemTypesSmoke: host override, item override, sort_order alternates

lang/en/lang.yaml

@@ -131,6 +131,8 @@ tag:
   delete_confirm: Delete this tag?
   delete_success: Successfully deleted those tags.
   return_to_tags: Return to the journal tag list
+menuitem:
+  journal_post: Journal post
 scopes:
   journal: Journal
   journal_description: Create, edit, publish and delete posts as you, within your Journal permissions.

lang/pl/lang.yaml

@@ -83,6 +83,8 @@ category:
   delete_success: Kategorie zostały pomyślnie usunięte.
   return_to_categories: Wróć do listy kategorii
   reorder: Zmień kolejność kategorii
+menuitem:
+  journal_post: Wpis (Journal)
 scopes:
   journal: Journal
   journal_description: Twórz, edytuj, publikuj i usuwaj posty jako Ty, w ramach swoich uprawnień Journal.