Reduce number of users initial loaded and replace by select2 - Import page

[pickplugins]

I would like to request to update normal behavior of "assign posts to an existing user:" loading all users during import.

I faced following issues
# taking longer time for big number of users.
# when clicking on select page got stacked or unresponsive.

Instead, we could replace by select2 or something like this, initially loaded admin roles users, and search to find targeted users via select2.

​https://ibb.co/Wt8wPgD

[joedolson]

Duplicate of #19867.

Closing as a duplicate. Thanks for reporting!