feat/fix: Added animated positioned implementation and fixed sdk issue

[sidheshwar-s]

issue - #283

Fix:

1) There was a syntax error in widgetList.dart.

2) Minimum sdk version for torch_light plugin is 21. Earlier it was 18.

3) Removed duplicate implementation of SimpleDialogCode class.

Feature:

Added implementation for the assigned issue

https://user-images.githubusercontent.com/84003394/138748795-53a896f2-da2f-4647-9286-8de70a7181f0.mp4

[acmbot[bot]]

Thanks @sidheshwar-s, for opening the pull request! 🙌 One of our team-mates will review the pull request soon. ✅

[acmbot[bot]]

Congratulations @sidheshwar-s, your pull request is merged! 🎉 Thanks for your contributions. 🙌