Navigation item IDs and classes are inconsistent in multilingual sites

Postponing on 📌 Decouple from Toolbar module Needs review because presumably will be necessary to make changes on the tree manipulators.

Shortcut icon will also break if the title of the 'Shortcut' block is modified. This happens because ShortcutsNavigationBlock uses the title of the block as the class name. When the title changes, the class name also changes, which breaks the style.

  /**
   * {@inheritdoc}
   */
  public function build(): array {
    $shortcuts_items = [
      [
        'title' => $this->configuration['label'],
        'class' => $this->configuration['label'],
      ],
    ];

One solution is to use the 'id' of the block as the class name instead of the title. However, the navigation UI permits adding multiple blocks of the same type to the sidebar. If a user adds a second 'Shortcuts' block, the id of that block would be 'shortcuts_1,' and it will break the icon of the second block.

Marking unblocked since 🐛 Error: Call to a member function replace() on null Needs review was merged.

Requested changes addressed. I think it's ready for review.

This looks great! Thanks @plopsec.

Thanks all for the work and help! Merged :D

Automatically closed - issue fixed for 2 weeks with no activity.