fix(playlists): the selection band keeps to one row on a tablet, and a tick moves no row

Below xl the band's buttons are glyphs named in their tooltips, and the row it
replaces stays in the same grid cell, invisible, so the first tick leaves the
list where the second tap expects it. The test's row menu asked for the pins
unmocked, and the offline toast could land before the check: mocked.

frontend/src/i18n/locales/en/playlists.json

@@ -107,6 +107,7 @@
   "selectedCount_other": "{{count}} selected",
   "selectedHidden_one": "{{count}} more hidden by the filter",
   "selectedHidden_other": "{{count}} more hidden by the filter",
+  "selectedHiddenShort": "+{{n}}",
   "clearSelection": "Clear selection",
   "moveSelected": "Move to",
   "removeSelected": "Remove",

frontend/src/i18n/locales/hu/playlists.json

@@ -107,6 +107,7 @@
   "selectedCount_other": "{{count}} kijelölve",
   "selectedHidden_one": "további {{count}} a szűrő mögött",
   "selectedHidden_other": "további {{count}} a szűrő mögött",
+  "selectedHiddenShort": "+{{n}}",
   "clearSelection": "Kijelölés törlése",
   "moveSelected": "Áthelyezés ide",
   "removeSelected": "Eltávolítás",