Restore the Add Categories and Remove Categories functionality to the Entry Manager.

In EE v1 and EE v2 there was a way to add and remove categories to entries in bulk.

That functionality is missing in EE v3

There’s currently no way to retroactively manage entry assignments to categories in EE.

When we’re working with clients that have established blogs with 100s of entries, there’s now no way to quickly add/remove dozens of previous posts to a newly created entry without opening up each one, one-at-a-time and adding them to the new category.

This is really an important feature for managing existing content that’s going to make migrating clients into EE v3 much more difficult for us.