(cherry picked from commit b3131a6)

…ransferred to a new trigger (#31690)

The menu has some logic that detaches its lazy content when the animation is finished, however while the animation was running, the panel might've been picked up by another trigger. This ends up opening an empty menu panel to the new trigger.

These changes resolve the issue by checking if another trigger picked up the panel before detaching the lazy content.

Fixes #31687.

(cherry picked from commit b1514c4)

We already had the `index` inside `insertNode`, but we weren't passing it along to the context.

Fixes #31578.

(cherry picked from commit 4d0fc19)

Fixes the following issues with the disabled behavior of the CDK menu item:
* The item wasn't receiving focus like specified in the spec.
* There wasn't a proper way to style disabled items which led users to use `aria-disabled`.
* Clicking the disaled item didn't prevent the default behavior.

Fixes #31179.

(cherry picked from commit d61e35d)