Update query builder data selector for datasets (#18764)

* Add unit tests for schema utils

* Add data bucket step to DataSelector

* Go to next steps from the data bucket step

* Add different type of AccordionList icons layout

* Add back navigation from 'Raw Data' tab

* Fix selecting a database in 'Raw Data'

* Enable search on data bucket step

* Only render data bucket step if there are datasets

* Prevent opening the data bucket step without datasets

* Update picker search placeholder text

* Update searchable models

* Fix displaying datasets in search results

* Hide "Saved Questions" in "Raw Data" tab

* Encode data in schema str

* Add ability to request dataset virtual tables

* Support datasets in SavedQuestionPicker

* Use saved question picker for datasets too

* Add E2E tests

* Show dataset icon in search results

* Fix E2E selectors

* Fix AccordionList icon rendering

* Fix dataset can't be selected in search

* Fix data selector step hydration

* Fix JoinStep unit tests

* Fix dataset icon size in picker view

* Fix schema picker without datasets

* Fix DataSelector tests

* Fix error about null data selector step

* Move schema utils to `metabase/lib`

* Fix questions don't appear in pickers after created

* Fix JoinStep unit tests

* Test can create a question based on a dataset

* Simplify schema ID parsing

* Fix typo

* Fix search models

* Fix ellipsis character

* Fix "Raw Data" button click area

* Remove temp comment

* Fix URL in personal collection contents request