Make DesktopTaskView's icon handling more similar to standard TaskView

- Add back touch handling on icon to make task menu work again
- Add back a couple of UI state handling for icon
- Fixed pivot of TaskView to use overviewTaskThumbnailTopMarginPx for calculations
- No longer require `taskView.getTask().icon` to populate TaskMenuView as it's no longer used in the menu; for TaskMenuViewWithArrow, check iconView.drawable instead which will get copied into DragLayer
- Added menu item handling for DesktopTaskView, and aligned GroupedTaksView handling to same mechanism
- Refactored Screenshot and Modal shortcut availability check into TaskShortFactory for consistency with other shortcuts

Bug: 249371338
Test: manual
Flag: ACONFIG com.android.window.flags.enable_desktop_windowing_mode DEVELOPMENT
Change-Id: I22ee6a5ca3c16a1bd510b0910211823e8c0be71b