GHA CI: add checks for grid items order

Now all items under `QGridLayout` are required to be sorted. This allow
us to omit tabstop order. The tabstop order will follow the layout order.

The script can be invoked to fix wrong grid items order in .ui files:
```console
python check_grid_items_order.py file.ui
```

.pre-commit-config.yaml

@@ -1,6 +1,12 @@
 repos:
   - repo: local
     hooks:
+      - id: check-grid-order
+        name: Check items order in grid layouts
+        entry: .github/workflows/helper/pre-commit/check_grid_items_order.py
+        language: script
+        files: \.ui$
+
       - id: check-translation-tag
         name: Check newline characters in <translation> tag
         entry: .github/workflows/helper/pre-commit/check_translation_tag.py