Integrate new media workflow into QuickPress

[koopersmith]

QuickPress calls media_buttons() and has a textarea, which means that the new media workflow should Just Work. Right now, it doesn't. Let's fix that.

In [22072], by koopersmith:

Add QuickPress support for new media workflow.

• Adds the code required to include the new media scripts, styles, and settings to media_button().
• Improves script dependencies, namely making media-upload require media-views.
• Some CSS tweaks for the making the new button work well with QuickPress.

see #21390, fixes #22021.

[22072] is top-notch. Big step towards back compat.

Seems like it's broken again.

#22255 — Beta Media button disabled after publishing QuickPress post

There is a Quicktags instance for replying to comments on the dashboard and it uses wp_editor(). However QuickPress doesn't use wp_editor() so there's no JS to set wpActiveEditor for it. Adding a little JS to fix that.

In 22517:

QuickPress: add some JS to set wpActiveEditor when the title or content is focused, fixes #22021

Setting wpActiveEditor only on focus is insufficient — the "Add Media" button can be clicked without focusing either field. Also, we can simplify the selectors a bit, as well as leverage event delegation.

In 22542:

Media in QuickPress: Ensure wpActiveEditor is set when the "Add Media" button is clicked. fixes #22021, see #21390.

Replying to koopersmith:

Nice catch. Keep forgetting thet focusin is normalized in jQuery (it's ​not supported in Firefox).