Author Dropdown doesn't include more than 100 authors

[aaronjorbin]

This is whatever version is currently on https://make.wordpress.org/core . Maybe 0.9.0?

Issue Overview

The author drop down is limited to 100 users. This means that some authors default to writing a post in someone else's name

Steps to Reproduce (for bugs)

Add over 101 users to a site. Log in as one that isn't in the first 100 alphabetical.

This can be seen on make.wordpress.org/core if your first name is after Peter.

[youknowriad]

Since the API is paginated we'll need some virtual scroll loading or a search input

[danielbachhuber]

Closing in favor of #4622

Also related: #4623 #4632