Add user option to rotate table column headers (#12837)

* Add user option to rotate table column headers (#12558)

Wide column titles (e.g. "Temperature coefficient [±ppm/°C]") take a
lot of horizontal space for narrow data. Add a ROTATE_TABLE_HEADERS
user setting (Display Options) which renders table header titles
vertically via a scoped CSS class, following the implementation
sketch from the issue discussion.

* Format ROTATE_TABLE_HEADERS description per ruff-format

* add missing doc place

* Document ROTATE_TABLE_HEADERS setting in user settings docs

* docs: add changelog entry for rotated table headers option

---------

Co-authored-by: Matthias Mair <code@mjmair.com>

src/backend/InvenTree/common/setting/user.py

@@ -205,6 +205,12 @@ USER_SETTINGS: dict[str, InvenTreeSettingsKeyType] = {
         'default': False,
         'validator': bool,
     },
+    'ROTATE_TABLE_HEADERS': {
+        'name': _('Rotated Table Headers'),
+        'description': _('Display table column headers with rotated (vertical) text'),
+        'default': False,
+        'validator': bool,
+    },
     'SHOW_SPOTLIGHT': {
         'name': _('Show Spotlight'),
         'description': _('Enable spotlight navigation functionality'),