* DEV: Remove HTML setting type and sanitization logic.
We concluded that we don't want settings to contain HTML, so I'm removing the setting type and sanitization logic. Additionally, we no longer allow the global-notice text to contain HTML.
I searched for usages of this setting type in the `all-the-plugins` repo and found none, so I haven't added a migration for existing settings.
* Mark Global notices containing links as HTML Safe.
Major changes included:
- better support for screen readers
- trapping focus in modals
- better tabbing order in composer
- alerts on no content found/number of items found
- better autofocus in modals
- mini-tag-chooser is now a multi-select component
- each multi-select-component will now display selection on one row
To add an extra layer of security, we sanitize settings before shipping them to the client. We don't sanitize those that have the "html" type.
The CookedPostProcessor already uses Loofah for sanitization, so I chose to also use it for this. I added it to our gemfile since we installed it as a transitive dependency.
