Add Animated Page Transitions for Bottom Navigation Tabs

[VITianLalit]

Pull Request Title:

"Add Animated Page Transitions for Bottom Navigation Tabs"

Pull Request Description:

Overview: This pull request introduces animated page transitions for the bottom navigation tabs in the Flutter application. By utilizing a PageView and PageController, the app now supports smooth and visually appealing transitions between the Home, Explore, Favorite, and About pages.

Changes:

1. MainHome Widget:

   • Integrated PageView with a PageController to handle page transitions.
   • Updated the BlocBuilder to manage the PageController for synchronization with the current tab index.
   • Implemented the _onBackPressed method for handling back button presses with a toast message.

2. BottomNavBar Widget:

   • Updated to interact with the PageController from the MainHome state.
   • Added animation for page transitions using animateToPage method on tab selection.

3. IndexCubit:

   • Manages the state of the current tab index to facilitate page transitions.

Enhancements:

• User Experience: Provides a smoother and more interactive user experience with animated transitions between tabs.
• Code Maintenance: Improved state management for page navigation by centralizing the PageController logic within the MainHome widget.

Testing:

• Verified the smooth transition animations between all tabs.
• Ensured the back button functionality works as expected with the added toast notification.
• Confirmed the state management of the current tab index is functioning correctly across the app.

Screenshots/Screen Recording:

https://github.com/VaibhavCodeClub/learn/assets/98540540/0a273006-11e2-4eea-bf69-eb7b96d1210c

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This PR enhances the navigation experience by adding visually appealing animations, making the app more engaging and user-friendly. Please review the changes and provide feedback or approval for merging. fixes #189

[VITianLalit]

fixes issue #189