Fix pckgs deprecateds for functionality of project

[ThiagoEwer]

Hello man, I took this project of yours to practice a little dart and flutter, considering that it was a very important project during the pandemic, congratulations on the initiative.

So I decided to make some adjustments to keep it working and for that I needed to update the packages, as there were many obsolete ones. I also made some adjustments to the widgets used for the UI and finally I used google idx to compile and visualize its proper functioning and there it is!