UX improvements

* ignore English articles when sorting names
  * added a new sort_name field that gets automatically created
* automatically fill certain values in forms:
  * new game: name and sort name after typing
  * new edition: name and sort name when selecting game
  * new purchase: platform when selecting edition

games/static/js/add_game.js

@@ -0,0 +1,12 @@
+import { syncSelectInputUntilChanged } from './utils.js'
+
+let syncData = [
+  {
+    "source": "#id_name",
+    "source_value": "value",
+    "target": "#id_sort_name",
+    "target_value": "value"
+  }
+]
+
+syncSelectInputUntilChanged(syncData, "form")