Adds skeleton for "app settings" view

lib/settings/app_settings.dart

@@ -0,0 +1,73 @@
+
+import 'package:flutter/material.dart';
+import 'package:flutter/cupertino.dart';
+
+import 'package:flutter_gen/gen_l10n/app_localizations.dart';
+import 'package:font_awesome_flutter/font_awesome_flutter.dart';
+
+class InvenTreeAppSettingsWidget extends StatefulWidget {
+  @override
+  _InvenTreeAppSettingsState createState() => _InvenTreeAppSettingsState();
+}
+
+class _InvenTreeAppSettingsState extends State<InvenTreeAppSettingsWidget> {
+
+  final GlobalKey<_InvenTreeAppSettingsState> _settingsKey = GlobalKey<_InvenTreeAppSettingsState>();
+
+  _InvenTreeAppSettingsState() {
+
+  }
+
+  bool a = false;
+
+  @override
+  Widget build(BuildContext context) {
+
+    return Scaffold(
+      key: _settingsKey,
+      appBar: AppBar(
+        title: Text(I18N.of(context).appSettings),
+      ),
+      body: Container(
+        child: ListView(
+          children: [
+            ListTile(
+              title: Text(
+                "Sounds",
+                style: TextStyle(fontWeight: FontWeight.bold),
+              ),
+              leading: FaIcon(FontAwesomeIcons.volumeUp),
+            ),
+            ListTile(
+              title: Text("Server Error"),
+              subtitle: Text("Play audible tone on server error"),
+              leading: FaIcon(FontAwesomeIcons.server),
+              trailing: Switch(
+                value: false,
+                onChanged: (value) {
+                  setState(() {
+                    // TODO
+                  });
+                },
+              ),
+            ),
+            ListTile(
+              title: Text("Barcode Tones"),
+              subtitle: Text("Play audible tones for barcode actions"),
+              leading: FaIcon(FontAwesomeIcons.qrcode),
+              trailing: Switch(
+                value: a,
+                onChanged: (value) {
+                  setState(() {
+                    a = value;
+                  });
+                },
+              ),
+            ),
+            Divider(height: 1),
+          ]
+        )
+      )
+    );
+  }
+}