Updated filters after WordPress#28800, which introduced a remote call…

… to patterns directory to fetch and then register patterns.

This commit provides filters to opt out of:
1. removing core patterns, in case Gutenberg users want to use Core patterns
2. adding Gutenberg patterns
3. loading core patterns from remote source

lib/block-patterns.php

@@ -239,8 +239,16 @@ function() {
 		if ( ! get_theme_support( 'core-block-patterns' ) || ! function_exists( 'unregister_block_pattern' ) ) {
 			return;
 		}
-		remove_core_patterns();
-		register_gutenberg_patterns();
+
+		// Provides a way to opt-out of removing core patterns.
+		if ( apply_filters( 'remove_core_patterns', true ) ) {
+			remove_core_patterns();
+		}
+
+		// Provides a way to opt-out of pattern registration.
+		if ( apply_filters( 'register_gutenberg_patterns', true ) ) {
+			register_gutenberg_patterns();
+		}
 	}
 );
 
@@ -251,6 +259,11 @@ function( $current_screen ) {
 			return;
 		}
 
+		// Provides a way to opt-out of remotely loading core patterns.
+		if ( ! apply_filters( 'load_remote_patterns', true ) ) {
+			return;
+		}
+
 		$is_site_editor = ( function_exists( 'gutenberg_is_edit_site_page' ) && gutenberg_is_edit_site_page( $current_screen->id ) );
 		if ( $current_screen->is_block_editor || $is_site_editor ) {
 			load_remote_patterns();