Store result of RevisionOverviewForm::getRevisionIds to prevent paging bugs in subclasses

Problem/Motivation

The WSE module extends Diff's RevisionOverviewForm in order to add a "Workspaces" column to the revisions overview page.

See https://git.drupalcode.org/project/wse/-/blob/3.0.x/src/Diff/Form/WseRev...

The ::getRevisionIds() method gets called twice during a build of WseRevisionOverviewForm: once inside parent::buildForm() and then once directly with $this->getRevisionIds().

The problem is that these two queries end up using two different pagers. The result is that the Workspaces column does not paginate correctly.

See #3581936: Workspace column on revisions overview form does not respect pagination.

Steps to reproduce

1. Install WSE with Diff and create revisions for some node in various workspaces.
2. Either create more than 50 revisions or change the diff.general_settings.revision_pager_limit setting to some small number such that you can page the revisions overview form for the node.
3. Note that the Workspaces column does not reflect the pager.

Proposed resolution

While this could be fixed by overriding the method in WSE, I think it makes more sense to make a change in the Diff module itself.

Update Drupal\diff\Form\RevisionOverviewForm::getRevisionIds() such that the result is stored on a class property. That way when we call the same method from WSE we get the cached values instead of having the entity query run again. It's running the query a second time that is causing core's pager manager to get tricked into thinking there are multiple pagers.

Something like:

  /**
   * Gets a list of node revision IDs for a specific node.
   *
   * Only returns revisions that are affected by the $node language.
   *
   * @param \Drupal\node\NodeInterface $node
   *   The node entity.
   *
   * @return int[]
   *   Node revision IDs (in descending order).
   */
  protected function getRevisionIds(NodeInterface $node): array {
    if (isset($this->revisionIds[$node->id()])) {
      return $this->revisionIds[$node->id()];
    }
    $entityType = $node->getEntityType();
    $result = $this->entityTypeManager->getStorage('node')->getQuery()
      // Access to the content has already been verified. Disable query-level
      // access checking so that revisions for unpublished content still
      // appear.
      ->accessCheck(FALSE)
      ->allRevisions()
      ->condition($entityType->getKey('langcode'), $node->language()->getId())
      ->condition($entityType->getKey('revision_translation_affected'), '1')
      ->condition($entityType->getKey('id'), $node->id())
      ->sort($entityType->getKey('revision'), 'DESC')
      ->pager($this->config->get('general_settings.revision_pager_limit'))
      ->execute();
    $this->revisionIds[$node->id()] = \array_keys($result);
    return $this->revisionIds[$node->id()];
  }

Remaining tasks

User interface changes

API changes

Data model changes