Add native block-editor support

• Add wp-scripts for build
• Enqueue script, excluding it from widget block editor
• Localize script with configurable/filterable options
• Localize script with titles for post types to match current functionality
• Register meta and set sanitization callbacks
• Allow meta to be accessed via endpoint
• Create sidebar plugin to show the two fields used by the plugin

inc/class-external-permalinks-redux-block-editor.php

@@ -108,8 +108,8 @@ class External_Permalinks_Redux_Block_Editor {
 		}
 
 		if (
-			$meta_key === external_permalinks_redux::get_instance()->meta_key_target
-			|| $meta_key === external_permalinks_redux::get_instance()->meta_key_type
+			external_permalinks_redux::get_instance()->meta_key_target === $meta_key
+			|| external_permalinks_redux::get_instance()->meta_key_type === $meta_key
 		) {
 			return false;
 		}
@@ -161,18 +161,18 @@ class External_Permalinks_Redux_Block_Editor {
 	 */
 	protected function _get_status_codes() {
 		$codes = external_permalinks_redux::get_instance()->status_codes;
-		$formatted = [
-			[
+		$formatted = array(
+			array(
 				'label'    => __( '-- Select --', 'external-permalinks-redux' ),
 				'value'    => 0,
-			],
-		];
+			),
+		);
 
 		foreach ( $codes as $code => $label ) {
-			$formatted[] = [
+			$formatted[] = array(
 				'label' => $label,
 				'value' => $code,
-			];
+			);
 		}
 
 		return $formatted;