Update TAPL to operate on folder icons.

The change updates features listed as follow:

1. Create a new class for folder icon.
2. Implement function to drag a icon to the other.
   (create a folder)
3. Find folders in a workspace.

Bug: 199120092
Test: Launcher3Tests:com.android.launcher3.ui.TaplTestsLauncher3#testDragToFolder
Change-Id: I3044025f8297f6e442446d70238f4b56f38a798a