[Popper] Fix regression when an occluded submenu stays visible even with enabled hideWhenDetached flag

[nikita-miro]

Description

There seems to be a regression in react-popper component in versions 1.1.3 and newer, which affected submenus in scrollable menus.

Problem

When a menu is rendered, which

• Has hideWhenDetached flag enabled.
• Has a submenu.
• Has menu height short enough to require scrolling to see the submenu.

Then in the latest versions of react-menu component this submenu stays on screen even when its parent item is scrolled out of the visible area.

Behavior in react-popper 1.1.2 and this branch	Behavior in react-popper 1.1.3
Screen.Recording.2024-11-20.at.17.51.06.mov.mp4	Screen.Recording.2024-11-20.at.17.54.25.mov.mp4

Root cause

This regression seems to be caused by changes in this PR: #2185

• These changes blocked the default boundary detection strategy in Floating UI, because now Radix always sets a non-empty value to the boundary option passed to the hide middleware. Now an empty array is passed as boundary option, when no collisionBoundary prop is defined, instead of an undefined value in version 1.1.2.
• Because prior to version 1.1.3, we didn't pass boundary option at all, this let Floating UI fall back to its default clippingAncestors value. But because now we pass an empty array instead, which is a truthy value, the default fallback value is never used.

Proposed changes

This PR adds an extra check for undefined collisionBoundary prop. When it's not defined, then we don't override the default boundary value passed to Floating UI helpers either.

A few tweaks are also made to the <Menu> component's storybook to reproduce the issue and test the fix.