Blocks: Add context fields to WP_Block_Type

New block context related fields were added as part of https://github.com/WordPress/gutenberg/pull/22686. This changest backports them to WP_Block_Type class.

Props aduth, spacedmonkey, mcsf, epiqueras.
Fixes #47656.  



git-svn-id: https://develop.svn.wordpress.org/trunk@48117 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-wp-block-type.php

@@ -74,9 +74,9 @@ class WP_Block_Type {
 
 	/**
 	 * @since 5.5.0
-	 * @var array
+	 * @var array|null
 	 */
-	public $supports = array();
+	public $supports = null;
 
 	/**
 	 * @since 5.5.0
@@ -100,6 +100,22 @@ class WP_Block_Type {
 	 */
 	public $attributes = null;
 
+	/**
+	 * Context values inherited by blocks of this type.
+	 *
+	 * @since 5.5.0
+	 * @var array
+	 */
+	public $uses_context = array();
+
+	/**
+	 * Context provided by blocks of this type.
+	 *
+	 * @since 5.5.0
+	 * @var array|null
+	 */
+	public $provides_context = null;
+
 	/**
 	 * Block type editor script handle.
 	 *