MDL-81050 navigation: Add data attributes to sections in breadcrumbs

- Add a new method 'add_attribute' to navigation nodes to add HTML attributes to nodes.
- Add data-attribute to section nodes and include them in breadcrumb mustache to automatically update section titles
 when sections are renamed.

lib/navigationlib.php

@@ -116,6 +116,8 @@ class navigation_node implements renderable {
     public $forceopen = false;
     /** @var array An array of CSS classes for the node */
     public $classes = array();
+    /** @var array An array of HTML attributes for the node */
+    public $attributes = [];
     /** @var navigation_node_collection An array of child nodes */
     public $children = array();
     /** @var bool If set to true the node will be recognised as active */
@@ -559,6 +561,16 @@ class navigation_node implements renderable {
         return true;
     }
 
+    /**
+     * Adds an HTML attribute to this node.
+     *
+     * @param string $name
+     * @param string $value
+     */
+    public function add_attribute(string $name, string $value): void {
+        $this->attributes[] = ['name' => $name, 'value' => $value];
+    }
+
     /**
      * Removes a CSS class from this node.
      *
@@ -2290,6 +2302,7 @@ class global_navigation extends navigation_node {
                     null, $section->id, new pix_icon('i/section', ''));
                 $sectionnode->nodetype = navigation_node::NODETYPE_BRANCH;
                 $sectionnode->hidden = (!$section->visible || !$section->available);
+                $sectionnode->add_attribute('data-section-name-for', $section->id);
                 if ($this->includesectionnum !== false && $this->includesectionnum == $section->section) {
                     $this->load_section_activities($sectionnode, $section->section, $activities);
                 }