* Split main reducer from item reducer

* Move query related redux to separate file

* Split more parts and tests

* Fix import

* Remove unused code

* Update public/app/features/explore/state/datasource.ts

Co-authored-by: Zoltán Bedi <zoltan.bedi@gmail.com>

* Add section comments

* Rename ExploreItem to ExplorePane

* Fix imports

Co-authored-by: Zoltán Bedi <zoltan.bedi@gmail.com>