General: Add $schema property to block and theme JSON files.

Additionally, this changeset fixes some of the `block.json` and `theme.json` files in PHPUnit tests by adding missing `title` properties to satisfy the schema. Those changes have no impact on the runtime whatsoever and do not change the result of unit tests.

Note that some block and theme JSON files still aren't valid according to the schema. Fixing is underway; the required changes will be merged subsequently.

Props jonsurrell, dmsnell, gziolo.
Fixes #60255.
Built from https://develop.svn.wordpress.org/trunk@57336


git-svn-id: http://core.svn.wordpress.org/trunk@56842 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-content/themes/twentytwentytwo/theme.json

@@ -1,4 +1,5 @@
 {
+	"$schema": "https://schemas.wp.org/trunk/theme.json",
 	"version": 2,
 	"customTemplates": [
 		{

wp-includes/theme.json

@@ -1,4 +1,5 @@
 {
+	"$schema": "https://schemas.wp.org/trunk/theme.json",
 	"version": 2,
 	"settings": {
 		"appearanceTools": false,

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.5-alpha-57335';
+$wp_version = '6.5-alpha-57336';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.