Fixing bugs in labels.dart

[BhavaniSaranga12]

Description:

1. In labels.dart file, the favProviderModel.add() expects a parameter of type int but container widget is used and hence the labels can't be added to favourites.
2. In widget_category.dart file, the BottomNavBarScreen() is undefined.
3. undefined customTextButtonColor

The above issues can be solved by changing their respective files and favourite provider files.

I would like to raise a PR with proper solution , @Debajyoti14 @ashdude1401 Please assign me this issue.

[Vibhav70]

I want to work on this issue. Please assign me this issue.

[puneethkumar18]

I am interested to resolve this Please assign me @Roshaen