Editor: add lightbox setting.

Adds lightbox as a valid setting to `WP_Theme_JSON` class and as an image block setting in theme.json.

Props czapla, costdev, desrosj.
Fixes #59393.


git-svn-id: https://develop.svn.wordpress.org/trunk@56643 602fd350-edb4-49c9-b593-d223f7449a82

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

@@ -343,7 +343,7 @@ class WP_Theme_JSON {
 	 *              `position.fixed` and `position.sticky`.
 	 * @since 6.3.0 Added support for `typography.textColumns`, removed `layout.definitions`.
 	 * @since 6.4.0 Added support for `layout.allowEditing`, `background.backgroundImage`,
-	 *              and `typography.writingMode`.
+	 *              `typography.writingMode`, `lightbox.enabled` and `lightbox.allowEditing`.
 	 * @var array
 	 */
 	const VALID_SETTINGS = array(
@@ -384,6 +384,10 @@ class WP_Theme_JSON {
 			'wideSize'     => null,
 			'allowEditing' => null,
 		),
+		'lightbox'                      => array(
+			'enabled'      => null,
+			'allowEditing' => null,
+		),
 		'position'                      => array(
 			'fixed'  => null,
 			'sticky' => null,

src/wp-includes/theme.json

@@ -272,6 +272,11 @@
 					"radius": true
 				}
 			},
+			"core/image": {
+				"lightbox": {
+					"allowEditing": true
+				}
+			},
 			"core/pullquote": {
 				"border": {
 					"color": true,