This commit also fixes a deprecation warning as the previous component was overriding a computed property from the group model.
Finally a test has been added as this is the only place where we use list-setting outside of the settings, this was highly subject to regressions.
* Calling `Discourse.reset()` creates a new container
We should run our de-initializers only after acceptance tests,
since initializers are not run outside of acceptance tests anyway,
and the container at this point can be passed properly to the
`teardown()` method.
* Remove `Discourse.reset` from tests
This would cause a new container to be created which leaks many objects.
* `updateCurrentUser` is more accurate than `replaceCurrentUser`
