Resolve "Events"

What is in this MR

This MR introduces the new event system that can be used to trigger actions.

It's the prerequisite to the actions implementation.

This MR does not include an exhaustive implementation of all the various events on all the various elements. It is merely the first MR to understand if we like the architecture in mind. If the changes here are approved then we can proceed to implement more events for more elements.

How to test this MR

• Create a new page
• Add a button
• Go to the Events tab
  • See that is should say On click
  • You can't do anything here yet, just notice that it exists
• Open the preview
• Open your dev tools
• Click the button
  • Notice that it logged a message to the console

Merge Request Checklist

• changelog.md has been updated if required.
• New/updated Premium/Enterprise features are separated correctly in the premium or enterprise folder
• The latest Chrome and Firefox have been used to test any new frontend features
• Documentation has been updated
• Quality Standards are met
• Performance: tables are still fast with 100k+ rows, 100+ field tables
• The redoc API pages have been updated for any REST API changes
• Our custom API docs are updated for changes to endpoints accessed via api tokens
• The UI/UX has been updated following UI Style Guide

Closes #1960 (closed)