Enable "Remove from mistakes" in Single Task Page

[hemme]

This PR extends the functionality to ignore a mistake (previously available only in the TaskPreviewTile grid) to the TaskActionBar within the SingleTaskPage.
Users can now remove a task from their "My Mistakes" collection directly while reviewing the task details. This menu item is contextual: it only appears when the task is opened specifically from the My Mistakes page.

The new menu item, in single task (mistake) page:

The existing menu item, in My Mistakes page:

Key Changes

• UX & Localization:
  • The action label has been changed from the generic "Hide task" to "Remove from mistakes" to clearly indicate that the task is being removed from My Mistakes collection, not the entire app.
  • Added localized strings for this label in: EN, IT, ES, DE, RO, RU, ZH.
• Routing (SingleTaskRouteArguments): Added an optional onHideTask VoidCallback to the route arguments.
• Navigation: Updated the navigation logic to pass a callback that triggers the existing hide logic (updating StatsDB and modifying the local list) and subsequently closes the task page.
• UI Propagation: Updated SingleTaskPage and _SideBar constructors to accept the callback and propagate it down to the TaskActionBar.
• Action Bar: Added a conditional PopupMenuItem to the menu.

How to Test

1. Navigate to the My Mistakes page.
2. Tap on any task to open the Single Task view.
3. Open the menu in the bottom action bar (or sidebar on wide screens).
4. Verify: The option "Remove from mistakes" (or the localized equivalent) is visible.
5. Tap the option.
6. Verify: The task page closes, and the task is removed from the "My Mistakes" list.
7. Regression Test: Open a task from a standard category (e.g., "Life and Death"). Verify that this option is not present in the menu.