JQL search using WAS operator and BY predicates does not auto populate username or Account ID based on string

Issue Summary

When searching JQL using the WAS operator it is possible to easily construct a JQL query to see which user made a specific change.
For example, if you wanted to know if user jsmith changed the status of an issue to done, you could find these with:

status WAS Done BY jsmith 

However the problem comes here in Cloud are two fold:

1. Cloud isn't using usernames in the same manner as Server/DC does now. Hence not all Atlassian Account IDs have a true username, but rather an email address and Account ID instead. The Account ID can be used in this WAS operator if you know it. Email address cannot be used here.
2. The other problem here is that the issue navigator in Jira Cloud will not attempt to autocomplete the username or Account ID based on the input here. This feels inconsistent with the behavior that is displayed for assignee or reporter fields. When you search those fields, the issue navigator will attempt to search for users that match that string in some way.

Steps to Reproduce

1. In the issue navigator attempt to type out a search such as

   status WAS Done BY jsmit
   

Expected Results

When typing this out, we would expect that Jira would show you a list of any users that match that string of 'jsmit' so far and let you select one.

Actual Results

• The Issue Navigator does not offer any possible suggestion based on the input string here.
• This makes it very difficult for Jira Cloud users to utilize JQL in order to quickly and easily find these issues that were changed by a specific individual.

Workaround

It is possible to instead use the Account ID of the user and use that to query in JQL. However, you have to do some other work first to find this value, which feels overly tedious. You can find this in a few different ways:

1. You could load the user's profile, and then see the Account ID portion in the URL of that page. The URL tends to look something like this https://********.atlassian.net/people/5bb7ad0ccc53fd07601037802 where '5bb7ad0ccc53fd07601037802' would be the Account ID without quotes.
2. Alternatively, you can run a different JQL query such as

   assignee='Full Name' 
   

   Today Jira Cloud will automatically convert that selected user's name into the Account ID which can then be used in this other query in place of the username value.