This commit introduces several improvements to the pinned tab manager:
- **Adds icon support for pinned tabs**: Pinned tabs now store and restore their icon in addition to URL and title.
- **Adds "Replace with Current" context menu option**: A new option in the tab context menu allows replacing the URL of a pinned tab with the current page.
- **Refactors code for better readability**: Renames methods and variables for clarity, and improves code structure.
- **Fixes issues with resetting pinned tabs**: Ensures that pinned tabs are correctly reset when closed using the Ctrl+W shortcut or by using the "Reset Pinned Tab" context menu option.
- **Adds missing menu item**: Adds the missing menu item for resetting the pinned tab in the tab context menu.
These changes enhance the functionality and user experience of the pinned tab manager, making it more robust and user-friendly.
This commit introduces a new feature: a pinned tab manager.
- Adds `ZenPinnedTabsObserver` to listen for pinned/unpinned tab events.
- Implements `ZenPinnedTabManager` to handle the logic of managing pinned tabs:
- Stores pinned tab URLs and titles.
- Resets the pinned tab to its saved state when closed.
- Adds a new context menu option to manually reset a pinned tab.
- Implements a shortcut to close a pinned tab and optionally reset its state.
This feature enhances pinned tab functionality by providing a better user experience for managing and resetting them.
