Implement placement mode for QS edit page

Double tapping a tile will enter placement mode. This mode highlights the selected tile and greys out the rest. Tapping on any tile will move the selection to this position. This enables users to reposition tiles without dragging motion.

Test: manually
Test: EditModeTest
Test: EditTileListStateTest
Test: MutableSelectionStateTest
Fixes: 379116386
Flag: com.android.systemui.qs_ui_refactor_compose_fragment
Change-Id: I287d52e7f264379d547b6a45bed4b7795a8608fc