Retain recommendations (if possible) while picker is open

Picker rebinds recommendations when size constraints change or
fold/unfold, but recommendations from popup provider may have changed.
This is an attempt at trying to maintain currently shown items
as much possible.

Also, align the pagination and title to the top in two pane picker
 (confirmed with David that we prefer this version)

Additionally, we don't show the widgets count for suggestions.

Bug: 318410881
Flag: ACONFIG com.android.launcher3.enable_categorized_widget_recommendations DEVELOPMENT
Test: Manual

Change-Id: I60799f9ad38da913c3e084d758f5b82c79cd641c