CAKE-49 | deleted base send widget, base exchange widget and top panel; added extendBodyBehindAppBar property and transparent AppBar style to base page; refactored send page, send template page, exchange page and exchange template page

lib/src/widgets/top_panel.dart

@@ -1,44 +0,0 @@
-import 'package:flutter/material.dart';
-
-class TopPanel extends StatefulWidget {
-  TopPanel({
-    @required this.widget,
-    this.edgeInsets = const EdgeInsets.all(24),
-    this.color,
-    this.gradient
-  });
-
-  final Color color;
-  final Widget widget;
-  final EdgeInsets edgeInsets;
-  final Gradient gradient;
-
-  @override
-  TopPanelState createState() => TopPanelState(widget, edgeInsets, color, gradient);
-}
-
-class TopPanelState extends State<TopPanel> {
-  TopPanelState(this._widget, this._edgeInsets, this._color, this._gradient);
-
-  final Color _color;
-  final Widget _widget;
-  final EdgeInsets _edgeInsets;
-  final Gradient _gradient;
-
-  @override
-  Widget build(BuildContext context) {
-    return Container(
-      width: double.infinity,
-      padding: _edgeInsets,
-      decoration: BoxDecoration(
-        borderRadius: BorderRadius.only(
-          bottomLeft: Radius.circular(24),
-          bottomRight: Radius.circular(24)
-        ),
-        color: _color,
-        gradient: _gradient
-      ),
-      child: _widget,
-    );
-  }
-}