JQL WAS searches should be able to map out a renamed user to the user_key stored in the issue change history

Summary

JQL WAS searches should be able to map out a renamed user to the user_key stored in the issue change history. At the moment, you need to type in the old username (user_key) to retrieve results.

Steps to Reproduce

1. Create an issue.
2. Assign it to a user with username (and user_key) fred
3. Assign it to another user (e.g. admin)
4. Rename fred to fred_normal.
5. Perform a JQL search for assignee WAS fred_normal

Expected Results

The issue created in step 1 is returned in the search results.

Actual Results

The issue created in step 1 is not returned in the search results.

Workaround

Perform the JQL WAS search using the old username (user_key).

In the example from the reproduction scenario above, assignee WAS fred