Block Editor: Update packages and backport the latest Gutenberg fixes.

This includes the following fixes:

- Generate babel polyfill dynamically https://github.com/WordPress/gutenberg/pull/31279
- Improve the List View component https://github.com/WordPress/gutenberg/pull/31290 https://github.com/WordPress/gutenberg/pull/32063
- Template mode:
    - Fix embed dimensions https://github.com/WordPress/gutenberg/pull/32057
    - Update the welcome guide https://github.com/WordPress/gutenberg/pull/32055 https://github.com/WordPress/gutenberg/pull/32026
    - Don’t display the notice at the same time as the welcome guide https://github.com/WordPress/gutenberg/pull/32076
    - Remove MetaBoxes https://github.com/WordPress/gutenberg/pull/32315
    - Update the title area https://github.com/WordPress/gutenberg/pull/32037 
- Widgets Screen:
    - Fix unsaved changes https://github.com/WordPress/gutenberg/pull/31757
    - Fix toolbar alignment https://github.com/WordPress/gutenberg/pull/31991
    - Fix block toolbar position after scroll https://github.com/WordPress/gutenberg/pull/32212
    - Fix the visible widget area header https://github.com/WordPress/gutenberg/pull/32262
    - Fix legacy widgets preview https://github.com/WordPress/gutenberg/pull/32260
    - 
- Block Widgets in the customizer: 
    - Fix customizer title overlapping block toolbar https://github.com/WordPress/gutenberg/pull/32140
    - Fix styling issues https://github.com/WordPress/gutenberg/pull/32072
    - Fix escape key events https://github.com/WordPress/gutenberg/pull/32175
    - Add preferences menu group label https://github.com/WordPress/gutenberg/pull/32259
    - Fix creating and replacing legacy widgets https://github.com/WordPress/gutenberg/pull/32005
    - Fix the welcome guide’s image https://github.com/WordPress/gutenberg/pull/32264 https://github.com/WordPress/gutenberg/pull/32302 
- Fix Cover to Image transform duotone error https://github.com/WordPress/gutenberg/pull/32006
- Remove filter_var usage from blocks https://github.com/WordPress/gutenberg/pull/32046 
- Fix image width for aligned Post Featured Image block https://github.com/WordPress/gutenberg/pull/32070
- Prevent excessive Image block re-rendering https://github.com/WordPress/gutenberg/pull/32102
- Remove gutenberg domain from core blocks https://github.com/WordPress/gutenberg/pull/32152
- Use the block editor context class for the the different settings filters https://github.com/WordPress/gutenberg/pull/32159
- Fix Latest Posts block grid view https://github.com/WordPress/gutenberg/pull/32160
- Fix preset classes generation per block https://github.com/WordPress/gutenberg/pull/32190
- Fix logic to enable custom colors and gradients https://github.com/WordPress/gutenberg/pull/32200
- Update the Site Logo logic to use a dedicated site option https://github.com/WordPress/gutenberg/pull/32229
- Limit the Latest Posts block’s featured image width https://github.com/WordPress/gutenberg/pull/32245
- Remove opacity animation in the canvas. https://github.com/WordPress/gutenberg/pull/32266
- Make the focus style valid CSS https://github.com/WordPress/gutenberg/pull/32305
- Fix theme.json styles for the core/list block https://github.com/WordPress/gutenberg/pull/32343
- Fix PHP notice when calling render_block https://github.com/WordPress/gutenberg/pull/32135

Props nosolosw, noisysocks.
See #52991.


git-svn-id: https://develop.svn.wordpress.org/trunk@51051 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-wp-theme-json.php

@@ -609,6 +609,28 @@ class WP_Theme_JSON {
 		return $selector . '{' . $declaration_block . '}';
 	}
 
+	/**
+	 * Function that appends a sub-selector to a existing one.
+	 *
+	 * Given the compounded $selector "h1, h2, h3"
+	 * and the $to_append selector ".some-class" the result will be
+	 * "h1.some-class, h2.some-class, h3.some-class".
+	 *
+	 * @param string $selector Original selector.
+	 * @param string $to_append Selector to append.
+	 *
+	 * @return string
+	 */
+	private static function append_to_selector( $selector, $to_append ) {
+		$new_selectors = array();
+		$selectors     = explode( ',', $selector );
+		foreach ( $selectors as $sel ) {
+			$new_selectors[] = $sel . $to_append;
+		}
+
+		return implode( ',', $new_selectors );
+	}
+
 	/**
 	 * Given a settings array, it returns the generated rulesets
 	 * for the preset classes.
@@ -633,7 +655,7 @@ class WP_Theme_JSON {
 			foreach ( $values as $value ) {
 				foreach ( $preset['classes'] as $class ) {
 					$stylesheet .= self::to_ruleset(
-						$selector . '.has-' . $value['slug'] . '-' . $class['class_suffix'],
+						self::append_to_selector( $selector, '.has-' . $value['slug'] . '-' . $class['class_suffix'] ),
 						array(
 							array(
 								'name'  => $class['property_name'],