changed primary color usage to fix the color bug in dark mode

Changed Theme.of(context).primaryColor to Theme.of(contex).colorScheme.primary to make dark mode work properly.

lib/features/beneficiaries/screens/manage_beneficiaries_screen.dart

@@ -75,7 +75,7 @@ class _ManageBeneficiariesScreen extends State<ManageBeneficiariesScreen> {
           leading: CircleAvatar(
             radius: 24,
             backgroundColor: Colors.transparent,
-            child: getBankLogo(item.bankName),
+            child: getBankLogo(item.bankName, context),
           ),
           title: Text(item.name),
           subtitle: Column(
@@ -122,8 +122,6 @@ class _ManageBeneficiariesScreen extends State<ManageBeneficiariesScreen> {
               ),
             );
           },
-          backgroundColor: Theme.of(context).scaffoldBackgroundColor,
-          foregroundColor: Theme.of(context).primaryColor,
           elevation: 5,
           child: const Icon(Icons.add),
         ),