title_bar: Add icon for project branch trigger button (#29494)

Added icon for branch switcher in title bar

| `main`    | This PR |
| -------- | ------- |
| <img width="196" alt="Screenshot 2025-04-27 at 1 02 47 PM"
src="https://github.com/user-attachments/assets/5625f6c5-7b11-4f3d-bed8-6ea3b74d9416"
/> | <img width="217" alt="Screenshot 2025-04-27 at 1 07 11 PM"
src="https://github.com/user-attachments/assets/6c83daa6-fa71-44a8-8f6b-e33b2217b29e"
/> |

Release Notes:

- Added icon for branch switcher in title bar

---------

Signed-off-by: Shashank Verma <shashank.verma2002@gmail.com>

assets/settings/default.json

@@ -307,6 +307,11 @@
     // Whether to show agent review buttons in the editor toolbar.
     "agent_review": true
   },
+  // Titlebar related settings
+  "title_bar": {
+    // Whether to show the branch icon beside branch switcher in the title bar.
+    "show_branch_icon": false
+  },
   // Scrollbar related settings
   "scrollbar": {
     // When to show the scrollbar in the editor.