Introduce Modifier.interactionBarrier() and implement pointer and accessibility blocking

Defines Modifier.interactionBarrier() and InteractionBarrierNode to block pointer events and accessibility (TalkBack) traversal for elements behind it.

Relnote: "Added Modifier.`interactionBarrier`() to block touch, focus, and accessibility interactions."
Test: ClipPointerInputTest, SemanticsTests
Bug: 347038246

Change-Id: I7c1b7c7fffd15081685ceb4818f36912b41031a1