Task/tp 2068 remove municipality guidance titles toc

[jussiviitamaki]

Actions necessary for applying the changes: (for example composer install; drush updb; drush cim)

Before checking out this branch: Login as admin and find service with municipality guide with h-elements in content and confirm the title shows up in TOC.
Also add an empty h5 element to some content field in internal work guidance and confirm an empty link shows up in TOC

Testing instructions:

• git checkout task/TP-2068_remove-municipality-guidance-titles-toc
• lando composer install && lando drush deploy
• Confirm deploy passes without problems
• Login as admin and go to service
• Confirm no there is no links to municipality guide content in TOC
• Confirm empty links in TOC have disappeared
• Confirm content still looks as it should

Review checklist:

• The code conforms to Drupal coding standards
• I have reviewed the code for security and quality issues
• I have tested the code with the proper user roles
• I have moved the ticket to the approval lane, added testing instructions and assigned it to the product owner.