TF-1808: Hanlde store email when opening email

(cherry picked from commit 2c895379f83b34e9bafb7545b21d790d01d444af)

core/lib/utils/file_utils.dart

@@ -55,7 +55,7 @@ class FileUtils {
     return await file.writeAsString(content, mode: FileMode.append);
   }
 
-  Future<String> getFromFile({
+  Future<String> getContentFromFile({
     required String nameFile,
     String? folderPath,
     String? extensionFile
@@ -73,6 +73,20 @@ class FileUtils {
 
     return emailContent;
   }
+
+  Future<bool> isFileExisted({
+    required String nameFile,
+    String? folderPath,
+    String? extensionFile
+  }) async {
+    final internalStorageDirPath = await _getInternalStorageDirPath(
+      nameFile: nameFile,
+      folderPath: folderPath,
+      extensionFile: extensionFile
+    );
+
+    return File(internalStorageDirPath).exists();
+  }
 }
 
 enum ExtensionType {

core/test/utils/file_utils_test.dart

@@ -30,7 +30,7 @@ void main() {
       /// Create a temporary file that will be deleted after `getFromFile` is done
       final file = await FileUtils().saveToFile(nameFile: fileName, content: fileContent);
 
-      final htmlString = await FileUtils().getFromFile(nameFile: fileName);
+      final htmlString = await FileUtils().getContentFromFile(nameFile: fileName);
 
       expect(htmlString.isNotEmpty, equals(true));