First commit of extensions to permissions.yml files (issue #3495351).

Closes #3495351

core/modules/user/src/Attribute/PermissionsParser.php

+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\user\Attribute;
+
+use Drupal\Component\Plugin\Attribute\Plugin;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+
+/**
+ * Defines a PermissionsParser attribute for plugin discovery.
+ *
+ * Plugin Namespace: Plugin\PermissionsParser.
+ */
+#[\Attribute(\Attribute::TARGET_CLASS)]
+class PermissionsParser extends Plugin {
+
+  /**
+   * Constructs a PermissionsParser object.
+   *
+   * @param string $id
+   *   The plugin ID.
+   * @param \Drupal\Core\StringTranslation\TranslatableMarkup|null $label
+   *   The title of the parser.
+   * @param \Drupal\Core\StringTranslation\TranslatableMarkup|null $description
+   *   The description of the parser.
+   * @param int $weight
+   *   The ordering of the parser in lists.
+   * @param bool $legacy
+   *   If this is legacy data or not.
+   */
+  public function __construct(
+    public readonly string $id,
+    public readonly ?TranslatableMarkup $label = NULL,
+    public readonly ?TranslatableMarkup $description = NULL,
+    public readonly int $weight = 0,
+    public readonly bool $legacy = FALSE,
+  ) {}
+
+}