Global Styles: Re-add third party blocks

[scruffian]

What?

This outputs Global Styles CSS for third party blocks.

Why?

Third party blocks should be able to consume Global Styles settings as well as core blocks.

How?

Since we can't predict the name for CSS files used for third party blocks, we need to add the block CSS to the global-styles inline CSS.

Testing Instructions

1. Add some third party blocks to a post (I'm using the Woo mini cart and Jetpack Tiled Gallery)
2. Add this code to your theme.json:

			"jetpack/tiled-gallery": {
				"color": {
					"background": "yellow"
				}
			},
			"woocommerce/mini-cart": {
				"color": {
					"background": "purple"
				}
			}

3. Or use the Global Styles interface to modify the settings for some third party blocks
4. Confirm that the blocks look correct in the frontend and the editor.

Screenshots or screencast

@WordPress/block-themers

[carolinan]

On the front, I am seeing the following:

Warning: Undefined array key "name" in /wp-content/plugins/gutenberg/lib/compat/wordpress-6.1/get-global-styles-and-settings.php on line 48

I tested three different blocks from two different plugins and the styling worked on two of them. I don't believe that is a problem with this PR but possibly with how that third block is built.

[t-hamano]

A rebase might be necessary because wp_add_global_styles_for_blocks has changed gutenberg_add_global_styles_for_blocks by #44052.

[ajlende]

@carolinan I think I fixed the warning you were getting. Give it another try.

[draganescu]

Tested this and works! The code LGTM

[bph]

@priethor @michalczaplinski @ockham should this be backport to 14.1, so it makes it into WP 6.1?

[ockham]

cc/ @c4rl0sbr4v0

[ockham]

should this be backport to 14.1, so it makes it into WP 6.1?

cc/ @oandregal for general Global Styles expertise and @sunyatasattva for Woo counseling 🙂

[scruffian]

I think this needs to be in 6.1

[cbravobernal]

Cherry-picked for 14.1

[ockham]

I just cherry-picked this PR to the wp/6.1 branch to get it included in the next release: 3b4341d

[oandregal]

Hey, did we backport this one? I don't see this changes in the current source at core https://github.com/WordPress/wordpress-develop/blob/trunk/src/wp-includes/global-styles-and-settings.php#L210

[ockham]

Uhhh, looks like we missed this one, since it's PHP code that requires manual backporting 🤦‍♂️

We'll file a PR now. I hope we'll manage to get it into 6.1 🤞

cc/ @c4rl0sbr4v0

[ockham]

We'll file a PR now. I hope we'll manage to get it into 6.1 🤞

Handled in WordPress/wordpress-develop#3529, which was merged to Core trunk in r54703, and to Core's 6.1 branch in r54705.

This means the fix should make it into 6.1 😌