Insert galleries into the text editor using the new media modal

[koopersmith]

We have a new media modal at #21390, but it's not particularly useful unless it integrates into our existing UI. Let's make it work for inserting galleries into the text editor.

For correctly ordering the attachments in the gallery, we'll need the gallery shortcode improvements from #21816.

[koopersmith]

In [22120]:

Use the new media modal to insert galleries into TinyMCE and the text editor.

Galleries

• Gallery insertion from the new media modal (into TinyMCE, the text editor, etc).
• Gallery previews in TinyMCE now use the wp.mce.views API.
• Disables the TinyMCE wpgallery plugin.
• Gallery previews consist of the first image of the gallery and the appearance of a stack. This will later be fleshed out to include more images/functionality (including editing the gallery, gallery properties, and showing the number of images in the gallery).
• Multiple galleries can be added to a single post.
• The gallery MCE view provides a bridge between the wp.shortcode and Attachments representation of a gallery, which allows the existing collection to persist when a gallery is initially created (preventing a request to the server for the query).

Shortcodes

• Renames wp.shortcode.Match to wp.shortcode to better expose the shortcode constructor.
• The wp.shortcode constructor now accepts an object of options instead of a wp.shortcode.regexp() match.
• A wp.shortcode instance can be created from a wp.shortcode.regexp() match by calling wp.shortcode.fromMatch( match ).
• Adds wp.shortcode.string(), which takes a set of shortcode parameters and converts them into a string.* Renames wp.shortcode.prototype.text() to wp.shortcode.prototype.string().
• Adds an additional capture group to wp.shortcode.regexp() that records whether or not the shortcode has a closing tag. This allows us to improve the accuracy of the syntax used when transforming a shortcode object back into a string.

Media Models

• Prevents media Query models from observing the central Attachments.all object when query args without corresponding filters are set (otherwise, queries quickly amass false positives).
• Adds post__in, post__not_in, and post_parent as acceptable JS attachment Query args.
• Attachments.more() always returns a $.promise object.

see #21390, #21809, #21812, #21815, #21817.

[pavelevap]

Is there any chance to filter inserted HTML or shortcode? I do not want to insert exact HTML for selected image, but for example my own shortcode [wpimage id="X"]?

[SergeyBiryukov]

#20426 was marked as a duplicate.