3506170 : Add "Submit issue about docs" to Drupal CMS docs pages

Closes #3506170

src/Plugin/Block/DrupalOrgDocumentationIssue.php

+<?php
+
+namespace Drupal\drupalorg\Plugin\Block;
+
+use Drupal\Core\Url;
+use Drupal\Core\Block\BlockBase;
+use Drupal\Core\Routing\RouteMatchInterface;
+use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Provides a 'DrupalOrg Documentation Issue Submission' Block.
+ *
+ * @Block(
+ *   id = "drupalorg_documentation_issue_submission",
+ *   admin_label = @Translation("DrupalOrg Documentation Issue Submission")
+ * )
+ */
+class DrupalOrgDocumentationIssue extends BlockBase implements ContainerFactoryPluginInterface {
+
+  /**
+   * The current route match.
+   *
+   * @var \Drupal\Core\Routing\RouteMatchInterface
+   */
+  protected RouteMatchInterface $routeMatch;
+
+  /**
+   * Constructs a new DrupalOrgDocumentationIssue instance.
+   *
+   * @param array $configuration
+   *   A configuration array containing information about the plugin instance.
+   * @param string $plugin_id
+   *   The plugin_id for the plugin instance.
+   * @param mixed $plugin_definition
+   *   The plugin implementation definition.
+   * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
+   *   The current route match.
+   */
+  public function __construct(array $configuration, $plugin_id, $plugin_definition, RouteMatchInterface $route_match) {
+    parent::__construct($configuration, $plugin_id, $plugin_definition);
+    $this->routeMatch = $route_match;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+    return new static(
+      $configuration,
+      $plugin_id,
+      $plugin_definition,
+      $container->get('current_route_match')
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function build() {
+    $node = $this->routeMatch->getParameter('node');
+
+    if ($node && $node->bundle() == 'documentation') {
+      $node_title = $node->getTitle();
+
+      $formatted_title = sprintf(
+        'Suggestion for: %s',
+        $node_title
+      );
+
+      // Get the absolute URL of the current node.
+      $node_url = $node->toUrl()->setAbsolute()->toString();
+
+      $url = Url::fromUri('https://www.drupal.org/node/add/project-issue/documentation', [
+        'query' => [
+          'title' => $formatted_title,
+          'body' => 'The documentation can be found at: ' . $node_url,
+        ],
+      ]);
+
+      return [
+        '#theme' => 'drupalorg_documentation_issue_submission',
+        '#url' => $url->toString(),
+      ];
+    }
+
+    return [];
+  }
+
+}