[Apps] Remove emitters (#25999)

* [Apps] Remove emitters

Emitters were created when we thought that we would be adding actions to
multiple places in metabase. Instead we've coalesced to actions being a
core feature of data-apps and are executed from within them. Attaching
actions to models, as a form of re-use rather than a form of execution,
means that actions can still be executed directly from a model, if we
want to allow that in the future.

* Fix lint errors

* Move perform-action! tests out of the api.

Since we want to keep the implicit bulk functionality but remove those
endpoints move the tests to the actions namespace.

* Fix linter

* Change driver test to use function instead of endpoint