Leave search events should fire when a search is deleted

[jde]

Expected behavior

When a search is deleted, a leave search event should be fired for each user that was in that search.

Actual behavior

The search is simply deleted without events for the users inside, effectively leaving them in a no longer existing search.

Steps to reproduce behavior

• Create a search with users.
• Watch the enter search events.
• Delete the search.
• Note no leave search events.

[kgardnr]

Closing as we are not actively developing on Trust at this time.