Add a few more gradients

lib/design_system/foundation/colors/internal_gradient.dart

@@ -1,7 +1,16 @@
+import 'package:concordium_wallet/design_system/foundation/colors/internal_color.dart';
 import 'package:flutter/material.dart';
 
 /// These are 'primitive' gradients that should never be referenced directly from code.
 /// They are only meant to be used internally by the semantic gradient tokens
 class InternalGradient {
-  static const disable = LinearGradient(begin: Alignment.centerLeft, end: Alignment.centerRight, colors: [Color(0xFFCCCCCC), Color(0xFFE5E5E5)]);
-}
+  static Gradient disable = _buildGradient(colors: const [InternalColor.black20, InternalColor.black10]);
+
+  // TODO(RHA): Is it intentional that the end color is missing?
+  static Gradient darkMineral = _buildGradient(colors: const [InternalColor.oceanBlue, Color(0xFF2E8894)]);
+  static Gradient lightMode = _buildGradient(colors: const [InternalColor.black05, InternalColor.white]);
+  static Gradient lightBlue = _buildGradient(colors: const []);
+
+  static Gradient _buildGradient({required List<Color> colors}) =>
+      LinearGradient(begin: Alignment.centerLeft, end: Alignment.centerRight, colors: [colors.first, colors.last]);
+}

lib/widgetbook/foundation/colors/view_gradients.dart

@@ -5,6 +5,8 @@ import 'package:widgetbook/widgetbook.dart';
 class ViewGradients {
   WidgetbookComponent get component => WidgetbookComponent(name: 'Gradients', useCases: [
         useCase('Disable', InternalGradient.disable),
+        useCase('Dark Mineral', InternalGradient.darkMineral),
+        useCase('Light Mode', InternalGradient.lightMode),
       ]);
 
   WidgetbookUseCase useCase(String name, Gradient gradient) => WidgetbookUseCase(