Extracting buttons below expanded QS to a separate view and controller

This is first part of showing utility bar (aka 3/4 buttons below expanded QS) in collapsed QS in split shade.
This change doesn't modify any behaviour/layout, just extracts utility bar to a separate layout (qs_footer_actions), view (QSFooterActionsView) and controller (QSFooterActionsController).
Next change will use this extracted entities to add utility bar to collapsed QS.

Bug: 195098483
Test: QSFooterActionsControllerTest + QSFooterViewControllerTest + all tests from com.android.systemui.qs

Change-Id: I5b49dd160bd777f12fd8696e56395830b2f81d30