Dialog view state preservation

[Vatsuki]

Hello, I have fixed the issue Dialog view is destroyed (state not preserved) when rotating the screen. #744 for the Notes application. I hope my contribution is correct. Let me know if I have to change something ^^

Type of change(s)

• Bug fix
• Feature / enhancement
• Infrastructure / tooling (CI, build, deps, tests)
• Documentation

What changed and why

• Replaced NewChecklistItemDialog and EditTaskDialog classes with ChecklistItemDialogFragment that inherits from DialogFragment.
• Implemented onSaveInstanceState to manually save/restore the text of rows. This was necessary because the dynamic rows share the same XML View ID, which confused the automatic state restoration.
• Replaced the previous lambda callbacks with setFragmentResult and setFragmentResultListener to safely pass data back to TasksFragment after the fragment recreation.

Tests performed

Tested on :

• Android Studio emulated "Medium Phone",
• Android 16,
• API 36.1
• White and Dark theme
• Maximized font size, display size in accessibility settings

Before & after preview

Before :
Check the original issue #744

After :

output.mp4

Closes the following issue(s)

FossifyOrg/General-Discussion#744 for the Notes applications

Checklist

• I read the contribution guidelines.
• I manually tested my changes on device/emulator (if applicable).
• I updated the "Unreleased" section in CHANGELOG.md (if applicable).
• I have self-reviewed my pull request (no typos, formatting errors, etc.).
• All checks are passing.