Implement new login page

[DGoiana]

• To the login with credentials keep the same popup, by now
• Care the gradient on the background

[pedroafmonteiro]

Screen_Recording_20241118_151200_One.UI.Home.mp4

Experimenting with the design.

• To add the gradient and animation to the splash screen I needed to add this package: https://pub.dev/packages/another_flutter_splash_screen

• The native splash screen was replaced by the same background color as the new splash and login page with a transparent logo image through this package: https://pub.dev/packages/flutter_native_splash

This is just an idea that will soon be implemented as a pull request (this was done in a separate app for testing)