Block API: Integrate variations with the / inserter

[gziolo]

Description

Follow-up for #16283.

With #19243, we integrate block variations API with the inserter. We still should seek a way to do a follow-up for the / inserter. At the moment, it only lists block types.

[mtias]

It's a bit unfortunate that the quick inserter is so separate from the main one. Changes to what gets listed there should propagate more easily.

[apeatling]

+1 to this. I just lost 40mins thinking I was doing something wrong because variations were not showing up, only to realize they don't show in the / inserter. 😆

[strarsis]

Is there already terminology for this kind of inserter?
"/"-Inserter
Quick-Inserter
Shortcut-Inserter
Fast-Inserter
?

[nk-o]

Really need this for our plugin with Gallery and Posts blocks:

[paaljoachim]

Let's see if I got this right.
One block can show up in multiple ways through the inserter panel.
I remember testing a PR some time ago where the Navigation showed up twice regular horizontal and a vertical mode. This is actually much more a layout choice / styles choice.

EDIT:
Meaning there should only be one Navigation Block in the '/' and the Inserter panel. Variations/layouts would exist in a block. See my comment here: #20584 (comment)

The example @nk-o shares seems to me more like styles and should be added to the Styles Panel. Having 5 options for the same block in the inserter is not the level it should be at.

[strarsis]

I remember testing a PR some time ago where the Navigation showed up twice regular horizontal and a vertical mode. This is actually much more a layout choice / styles choice.

Probably this issue.

[mtias]

@paaljoachim variations when exposed in inserter are to be considered new blocks, so they are meant to show up in all inserting contexts. What specific block choose to do is a separate conversation altogether.