feat(drawer, sheet): add withOverlay prop to control overlay rendering

[Harshul23]

Summary

This PR introduces a new withOverlay prop for both the Drawer and Sheet components.
It allows developers to optionally disable the overlay layer for cases where a transparent or inline experience is desired.

Context

Fixes #8493

Currently, the Drawer and Sheet components always render an overlay when open.
In some design scenarios (e.g. side panels, persistent drawers, nested overlays), developers may want to disable the overlay without forking the component.

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Changes

• Added optional withOverlay?: boolean prop (default: true) to:
  • DrawerContent
  • SheetContent
• Conditionally render overlay only when withOverlay is true
• Preserved accessibility and focus trapping behavior
• Maintained animation and scroll-lock logic compatibility
• Verified nested usage (Sheet inside Drawer) to avoid context conflicts
• Updated types and docs for new prop usage

Example Usage

<Drawer>
  <DrawerTrigger>Open Drawer</DrawerTrigger>
  <DrawerContent withOverlay={false}>
    <p>Overlay disabled example</p>
  </DrawerContent>
</Drawer>

Additional Notes

• Default behavior remains unchanged (backward-compatible)
• Ensured no breakage in nested dialog scopes (createDialogScope)
• Tested visually and via keyboard navigation

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