Scroll to selected tab after inserting to ensure that it is visible (#…

…642)

Task/Issue URL: https://app.asana.com/0/0/1202608828742665/f

Description:
If the item was inserted outside of collection's visible content rect, the collection needs
an explicit API call to scroll to reveal it.

DuckDuckGo/Tab Bar/View/TabBarViewController.swift

@@ -417,6 +417,7 @@ extension TabBarViewController: TabCollectionViewModelDelegate {
         collectionView.animator().insertItems(at: indexPathSet)
         if selected {
             collectionView.selectItems(at: indexPathSet, scrollPosition: .centeredHorizontally)
+            collectionView.scrollToSelected()
         }
 
         updateTabMode()