[Drawer] - blockScroll applies too late — scroll is not blocked during entrance animation

[kzana]

Describe the bug

When using the <Drawer> component with the blockScroll property enabled, there's a noticeable delay between opening the drawer and blocking the scroll on the body.

Specifically, the body remains scrollable during the entrance animation, and the scroll lock only applies after the animation finishes. This creates a flicker/glitch and allows users to scroll the background content momentarily, which breaks the expected modal behavior.

Expected behavior

As soon as the drawer is triggered to open, the scroll lock (overflow: hidden or equivalent) should be applied to the body before or at the same time the entrance animation begins — not after it ends.

Steps to reproduce

1. Enable blockScroll on the Drawer.
2. Open the Drawer (on a view with overflow-y).
3. Try scrolling the background during the entrance animation.
4. You'll notice scroll is possible until the animation ends.