Cw 973 in app gift card redemption flow plus UI (#2285)

* refactor: cleanup cake_pay folder

* refactor: add My Cards tab on the main screen

* ui: add user card item

* refactor: cakePay purchase flow

* feat: add user card info

* refactor: auth flow

* refactor: theme data

* revert

* Update qr_widget.dart

* fix: update with new themes

* minor fixes

* feat: put redemption flow under a feature flag

* feat: implement simulated purchasing flow in debug mode

* feat: support LTC and MWEB payments

* Update savings_page.dart

* fix: UI fixes

* add Cake Pay transaction sent bottom sheet

* localization

* Update cake_pay_buy_card_page.dart

* addressing review comments

* fix marge conflicts

lib/src/widgets/simple_checkbox.dart

@@ -0,0 +1,34 @@
+import 'package:flutter/material.dart';
+
+class SimpleCheckbox extends StatefulWidget {
+  SimpleCheckbox({this.onChanged});
+
+  final Function(bool)? onChanged;
+
+  @override
+  State<SimpleCheckbox> createState() => _SimpleCheckboxState();
+}
+
+class _SimpleCheckboxState extends State<SimpleCheckbox> {
+  bool initialValue = false;
+
+  @override
+  Widget build(BuildContext context) {
+    return SizedBox(
+      height: 24.0,
+      width: 24.0,
+      child: Checkbox(
+        value: initialValue,
+        onChanged: (value) => setState(() {
+          initialValue = value!;
+          widget.onChanged?.call(value);
+        }),
+        checkColor: Theme.of(context).textTheme.titleLarge!.color,
+        activeColor: Colors.transparent,
+        materialTapTargetSize: MaterialTapTargetSize.shrinkWrap,
+        side: WidgetStateBorderSide.resolveWith((states) => BorderSide(
+            color: Theme.of(context).textTheme.titleLarge!.color!, width: 1.0)),
+      ),
+    );
+  }
+}