feat(iOS, Stack): add basic header

[maciekstosio]

Description

Moved from: https://github.com/software-mansion/react-native-screens-labs/pull/140

This PR adds support for basic header (supporting just title atm). It follow the principles introduced by the bottom tabs.

Screen.Recording.2025-06-30.at.10.03.52.mov

Test code and steps to reproduce

See TestScreenStack.tsx

Checklist

• Included code example that can be used to test this change
• Updated TS types

[maciekstosio]

What's todo from the original PR review:

• investigate requesting appearance update, right now, after the first screen there is a delay in setting the appearance (it is visible when using), and sometimes it do not update
• replace passing RNSStackAppearance object with accessing header config from AppearanceCoordinator
• run iOS formatter, there is quiet a lot changes so I'd do it in separate PR and ignore the formatting in this PR