See BREAKING-CHANGES.txt for more details.

When AudioDeviceStop() is called from a thread other than the IO thread there are no guarantees about the IOProc being called before the thread actually terminates. Moving this call to the audioCallback() method ensures that the device will be stopped immediately and we can remove a check that was taking a few seconds to close devices.

This function is required by the Steinberg VST3 validator from VST 3.7
onwards.

When rendering with OpenGL, the paint function is called from a
background thread. If we call `isMouseOver` from the paint function, we
may end up calling native functions via the ComponentPeer, which causes
threading warnings on macOS.

This commit also removes the subview from its superview's subview array before re-ordering as the macOS docs don't make any guarantees about what happens when adding a subview that is already contained in the array.

This prevents components from taking focus when they are blocked by another modal component by excluding them from the list of child handlers returned by AccessibilityHandler::getChildren() and fixes an issue with modal components being dismissed by handlers.