Make Combined Feed a Main Navigation Tab

[E-m-i-n-e-n-c-e]

Make Combined Feed a Main Navigation Tab

Currently, the combined feed opens as a separate screen when clicked from the navigation bar. This PR changes it to be integrated as a main tab in the navigation, similar to Inbox and Channels.

Changes Made

1. Added combinedFeed to the _HomePageTab enum
2. Added the title for the combined feed tab in _currentTabTitle
3. Updated the navigation bar buttons to use the combined feed tab directly
4. Updated the menu button to use the tab instead of pushing to a new screen

Benefits

1. Better UX: The combined feed now behaves consistently with other main navigation items
2. State Preservation: The feed's state (scroll position, loaded messages) is preserved when switching tabs
3. Faster Navigation: No need to push/pop navigation stack when accessing the combined feed
4. Better User Experience: The page would reload every time you open it . Now users can have a better experience even if they are facing network issues

Testing

• Verify the combined feed loads correctly when switching to its tab
• Verify state is preserved when switching away and back to the combined feed
• Verify the menu item correctly switches to the combined feed tab
• Verify the app bar shows the correct title for the combined feed

Screenshots