Enhancement: Add Scale-up Animation and Glow Color Restriction for Selected Star

[YuneshShrestha]

This pull request introduces an enhancement to the codebase, addressing the following improvements:

1. Scale-up Animation: I've incorporated a smooth scale-up animation to provide a more engaging visual feedback when users interact with the rating stars.
2. Glow Color Restriction: I've limited the glowing effect to the star that is currently selected, offering a more intuitive and visually appealing rating experience.

Flexibility:
This feature is flexible.

code:

RatingBar(
          initialRating: 3,
          direction: Axis.horizontal,
          allowHalfRating: true,
          addScaleAnimation: true,
          itemCount: 5,
          ratingWidget: RatingWidget(
            full: Icon(Icons.star),
            half: Icon(Icons.star_half),
            empty: Icon(Icons.star_border),
          ),
          itemPadding: EdgeInsets.symmetric(horizontal: 4.0),
          glowColor: Colors.amberAccent,
          onRatingUpdate: (rating) {
            print(rating);
          },
        ),

Preview: