feat: Show confirmation before discarding unsaved Expense/Income

[Nigtim0]

Prerequisites

• I have searched for existing issues that already include this feature request, without success.

Describe the Feature Request

When I type any data in the "Add Expense" screen and then tap "Cancel" or back, the app just closes the screen without warning. This can cause accidental data loss.

Describe the Use Case

A confirmation dialog should appear, asking something like "Discard changes?" before closing.

Additional Information

No response

[jeffrey-zang]

Good idea, one caveat would be to only show that modal if the user has put any data in

[Nigtim0]

Exactly

[MiguelAcostaDelVecchio]

@jeffrey-zang @rarfell
This feature is implemented in #96

Let me know if it helps :)