Display official collection tooltips (#17453)

* Add tooltips to authority level configs

* Use tooltips for CollectionAuthorityLevelIcon

* Pass tooltips to getCollectionIcon result

* Display tooltip in CollectionHeader

* Display tooltip in collections sidebar

* Display tooltip on the homepage

* Display tooltip in ItemPicker

* Accept icon props as a TreeNode's icon prop value

* Display tooltip in saved question picker

* Accept icon props as a SelectListItem's icon prop value

* Display tooltip in dashboard's question picker

* Add "Belongs to an Official collection" tooltip

* Fix prop-types errors

* Add tests for CollectionAuthorityLevelIcon

* Add tests for isRegularCollection

* Fix search results collection icons

* Show "Official Collection" label in search results

* Don't show tooltips for official collections in search

* Fix ItemPicker's prop type

* Add basic test for ItemPicker

* Test read-only collections are not displayed

* Add test IDs to ItemPicker

* Refresh Redux store in each ItemPicker's test

* Test opening a nested collection

* Test default breadcrumbs state

* Fix ItemPicker's header test ID

* Test ItemPicker read-only items visibility

* Add test for onChange prop

* Test navigating back from an open collection

* Test personal collections are grouped in ItemPicker

* Assert number of ItemPicker items

* Test getCollectionIcon in EE

* Add a workaround for tooltip offsets

* Add describe block for CollectionsList tests

* Make CollectionsList test shorter

* Test collection types on CollectionList

* Fix SearchResult's info

* Add SearchResult tests

* Use isRegularCollection for AuthorityLevelIcon