New Select: Try it out with some core components (#92826)

* Export Combobox and add portalling

* Use floatingui fixed strategy and fix z-index

* Check non null

* Make value string type only

* Try with fiscal year setting

* Use combobox for WeekStartPicker

* Improve screen reader handling

* Fix faulty import

* Fix type issue

* Fix failing tests and export unstable

* Rename option and remove export

* Use comboboxMockSetup function

* Add support for number type

* menuClosed styles to emotion

packages/grafana-ui/src/unstable.ts

@@ -10,3 +10,4 @@
  */
 
 export * from './utils/skeleton';
+export * from './components/Combobox/Combobox';