feat(bar): add workspace numbers to TaskbarGrouped widget

Add workspace number badges to TaskbarGrouped widget that display in the
top-left corner of task groups, similar to existing Workspace widget
styling.

Features:
- Circular workspace number badges with negative margins for border overlap
- Color states: focused (primary), urgent (error), occupied (secondary), empty (outline)
- Burst animation effects when workspace becomes focused
- User-configurable settings: showWorkspaceNumbers, showNumbersOnlyWhenOccupied
- Comprehensive internationalization support for all supported locales

Implementation:
- Enhanced TaskbarGrouped.qml with workspace number display and animation system
- Created TaskbarGroupedSettings.qml for user configuration
- Updated BarWidgetRegistry.qml with default settings metadata
- Added settings dialog mapping in BarWidgetSettingsDialog.qml
- Added translations for all supported locales (en, de, es, fr, pt, zh-CN, uk-UA)

The workspace numbers provide quick visual identification of workspace
assignment while maintaining the clean aesthetic of the taskbar.

Services/BarWidgetRegistry.qml

@@ -146,7 +146,9 @@ Singleton {
                                     "colorizeIcons": false
                                   },
                                   "TaskbarGrouped": {
-                                    "allowUserSettings": true
+                                    "allowUserSettings": true,
+                                    "showWorkspaceNumbers": true,
+                                    "showNumbersOnlyWhenOccupied": true
                                   },
                                   "Tray": {
                                     "allowUserSettings": true,