Fix: Corrected state management issue in BookmarkMonumentsBloc #190

[dikshantbhangala]

#190 done

Changes Done:

1. Error Handling Improvements:

• Added proper error handling in the BookmarkMonumentsBloc for the following methods:
• _mapBookmarkMonumentToState
• _mapUnbookmarkMonumentToState
• _mapCheckIfMonumentIsBookmarkedToState
• _mapGetBookmarkedMonumentsToState
• Ensured the application emits the correct error state (BookmarkedMonumentsErrorState) when exceptions occur.

2. State Management Fixes:

• Replaced the undefined BookmarkMonumentsError with BookmarkedMonumentsErrorState to resolve the crash caused by undefined states.

3. Consistent State Emission:

• Modified the bloc methods to emit updated states (BookmarkedMonumentsLoaded) after bookmarking or unbookmarking a monument.
• Ensured state consistency when checking if a monument is bookmarked or retrieving the list of bookmarked monuments.

4.Bug Fix:

• Fixed the issue where bookmarked monuments disappeared when viewing a monument’s detail page by ensuring state updates propagate correctly.

5.Code Refactor:

• Improved readability and maintainability by structuring bloc methods and catching exceptions for each operation.s

[dikshantbhangala]

@mdmohsin7 @jddeep plz review this pr and tell me any required modification needed?