Add a new panel "Actions"

[Gustry]

• At least to display them dynamically if they are found on local. (similar to the project thumbnail)
• It allows us to add a link to the documentation to make our users aware :
  • https://docs.lizmap.com/current/fr/publish/configuration/action_popup.html
  • https://demo.lizmap.com/lizmap/index.php/view/map?repository=features&project=fire_hydrant_actions
• only later, we will allow edition

Side note, review and update documentation about actions, and mainly LWC 3.7 :

• Action module - new features lizmap-web-client#3343
• Module Action - Change the format of the JSON configuration file lizmap-web-client#3339