Transforms: Fixes Outer join issue with duplicate field names not getting the same unique field names as before  (#31121)

* Transformations: Fixed duplicate name issue in outer join transform

* Think this is working

* Updated tests

* Updated snapshot

* Fix broken tests (#31123)

* Fix broken tests

* Fix remaining faling tests

Co-authored-by: Giordano Ricci <gio.ricci@grafana.com>