Migrate field refs in visualization_settings.column_settings from legacy format (#30460)

* Create a migration for updating column_settings

* Make fn private

* Update test description

* Fix clj-kondo

* Migrate the entire vizualization_settings

* Add test for normalization and migration

* Update migration class name

* Use generate-string to improve key readability

* Add testing strings

* Fix migration

* transduce

* Add another test checking that `expected` is actually the up-to-date version

* Rework migration to only update field refs

* Use run!