feat(v6): introducing React Native Sheet

[gorhom]

🚀 Introducing React Native Sheet (v6)

This PR introduces a complete rewrite of the library to leverage the latest React Native technologies. This version is built from the ground up to support the New Architecture (Fabric/TurboModules), Reanimated 4, and Gesture Handler v3, providing a highly performant and flexible primitive for "Sheets" on all platforms.

📦 Rebranding: Bottom Sheet ⮕ Sheet

The library is being renamed to React Native Sheet. While "Bottom Sheet" was our origin, the new architecture allows the component to be anchored to any edge of the screen or behave as a free-floating modal.

🛠 Key Changes & Features

• New Architecture Support: Full compatibility with Fabric and TurboModules for synchronous layout calculations and improved performance.
• Reanimated & RNGH Integration: Utilizes the latest worklet-based APIs for fluid, 60/120fps interactions.
• Layout-Driven Logic: Rewritten internal logic that relies on React Native's layout engine rather than manual offset calculations, making it more robust.
• Native iPad & Landscape Support: Improved responsiveness and adaptive layouts. Sheets now behave predictably when orientation changes or when used in Split View on iPad.
• Unstyled & Customizable: We’ve moved toward a "Headless-ish" approach. Minimum default behaviors are enforced, giving developers full control over the UI, backdrop, and handle interactions.
• Flexible Positioning: No longer constrained to the bottom; supports various presentation styles (Side sheets, Top sheets, or centered).

⚠️ Breaking Changes

• Package Name: Transitioning from @gorhom/bottom-sheet to @gorhom/sheet.
• Default UI: Many default styles have been stripped to allow for better customization.

📝 To-Do / WIP

• Draft a technical design document.
• Update documentation site with the new branding.
• Add migration guide for v5 users.
• Finalize E2E testing for Fabric.