onboarding and minor layout fixes

[fres-sudo]

the minor layout fixes regards:

• month selector
• budgets provider (create another method "insertOrUpdates" in the budgets provider is also possible)
• add category page
• routes

[theperu]

Nice work! Most of the things look good to me, I just noticed a couple of issue that need to be fixed before merging:

1. When I close and reopen the app I see the onboarding again. Once the user completes the Onboarding the first time they should skip to the dashboard.
2. When I add the main account I can only input a number without the decimal points (Ex. I can add 3000 but not 3000.01)

Here is a video:
https://drive.google.com/file/d/1kiv-2eVfrE10KS8I2Y6FAEKEElZP4ypB/view?usp=drive_link

[fres-sudo]

Damn, I implement the one-time onboarding feature but for testing purpouse i commented it.
The idea was to uncomment it but i just forgot before committing >.<.
As you can see in main.dart at line 47/48 ther's the correct line and a TODO that explains everythings.

For the decimal point i'll take a look and see what i can do.

Thanks!

[theperu]

@lucaantonelli now it seems fine to me, if you agree we can merge 🙂