refactor: Switch to file_picker package and get rid of some dependency overrides

lib/pages/settings/settings.dart

@@ -3,7 +3,8 @@ import 'dart:async';
 import 'package:flutter/material.dart';
 
 import 'package:adaptive_dialog/adaptive_dialog.dart';
-import 'package:file_picker_cross/file_picker_cross.dart';
+import 'package:collection/collection.dart';
+import 'package:file_picker/file_picker.dart';
 import 'package:flutter_gen/gen_l10n/l10n.dart';
 import 'package:future_loading_dialog/future_loading_dialog.dart';
 import 'package:image_picker/image_picker.dart';
@@ -134,12 +135,15 @@ class SettingsController extends State<Settings> {
         name: result.path,
       );
     } else {
-      final result =
-          await FilePickerCross.importFromStorage(type: FileTypeCross.image);
-      if (result.fileName == null) return;
+      final result = await FilePicker.platform.pickFiles(
+        type: FileType.image,
+        withData: true,
+      );
+      final pickedFile = result?.files.firstOrNull;
+      if (pickedFile == null) return;
       file = MatrixFile(
-        bytes: result.toUint8List(),
-        name: result.fileName!,
+        bytes: pickedFile.bytes!,
+        name: pickedFile.name,
       );
     }
     final success = await showFutureLoadingDialog(