Add TaskFragmentParentInfo

This CL adds a TaskFragmentParentInfo class and extends
onTaskFragmentParentInfoChanged to dispatch display ID and
visibility of the parent Task.
It makes SplitController able to track visibility and display
changes and used to update SplitContainers if there's a folding
state change.

Test: atest SplitControllerTest TaskFragmentOrganizerControllerTest
Bug: 243609832
Bug: 207494880

Change-Id: If3d5db621b20d4005ce0b60e46ac98e1d1e962e3