feat(11.1-05): add the walkthrough's admin controller, publish command and published_at migration

- make:admin-controller, make:command and make:migration output, finished:
  the Posts controller serves models.Post behind acme.blog.access_posts,
  WinterCMS-style form and list YAML embedded through pact.AdminAssets,
  blog:publish sets published_at by slug with a bound parameter
- the posts route lists published posts only, newest first
- Docker tests migrate an ICU pl-PL database, roll back published_at, serve
  the route and run blog:publish with a published and an opened database
- the page gains the admin controller, console command and added-column
  sections

docs/examples/blog/controllers/posts/config_list.yaml

@@ -0,0 +1,13 @@
+list: ~/plugins/acme/blog/models/posts/columns.yaml
+modelClass: Post
+title: acme.blog::lang.posts.title
+recordUrl: acme/blog/posts/update/:id
+recordsPerPage: 20
+showCheckboxes: true
+defaultSort:
+    column: published_at
+    direction: desc
+toolbar:
+    buttons: [create, delete]
+    search:
+        prompt: backend::lang.list.search_prompt