In-app trial submission should give an alert for all possible paths

Summary

Currently after a user submits for trial creation in app /-/trials/create, we don't notify them that it was a success unless they are redirected to the overview of the group. Sometimes we redirect them to other places like discover security path and their stored path seen here. At those times no alert is shown.

Solution

render the ee/app/views/trials/_alert.html.haml or equivalent for those other cases. Perhaps this would mean merely moving this message into the controller layer as a flash, but then it would only show once and not on reload....which could be fine?