Remove Flushbar

With a FAB, flushbar's snackbar is just too difficult to press. We're
reverting to the classic Scaffold and making sure we're calling it with
the correct context.

https://github.com/AndreHaueisen/flushbar/issues/64

lib/utils.dart

@@ -2,8 +2,6 @@ import 'package:fimber/fimber.dart';
 import 'package:flutter/material.dart';
 import 'package:package_info/package_info.dart';
 
-import 'package:flushbar/flushbar.dart';
-
 import 'app.dart';
 import 'core/note.dart';
 import 'state_container.dart';
@@ -38,8 +36,6 @@ SnackBar buildUndoDeleteSnackbar(BuildContext context, Note deletedNote) {
 }
 
 void showSnackbar(BuildContext context, String message) {
-  Flushbar(
-    message: message,
-    duration: const Duration(seconds: 3),
-  ).show(context);
+  var snackBar = SnackBar(content: Text(message));
+  Scaffold.of(context).showSnackBar(snackBar);
 }

pubspec.lock

@@ -155,13 +155,6 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "5.0.9"
-  flushbar:
-    dependency: "direct main"
-    description:
-      name: flushbar
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.9.1"
   flutter:
     dependency: "direct main"
     description: flutter

pubspec.yaml

@@ -26,7 +26,6 @@ dependencies:
   auto_size_text: ^2.0.1
   fimber: ^0.3.0
   dynamic_theme: ^1.0.0
-  flushbar: ^1.9.0
   flutter_staggered_grid_view: ^0.3.0
   page_transition: "^1.1.5"
   provider: ^3.2.0