Previously the image was imported from a Discourse hosted CDN but the
URL has since become invalid. However, it was not caught since all
errors are rescued. This commit fixes the issue by shipping the user
avatar with the plugin.
* Rename all instances of bookmarkWithReminder and bookmark_with_reminder to just bookmark
* Delete old bookmark code at the same time
* Add migration to remove the bookmarkWithReminder post menu item if people have it set in site settings
This is to streamline the new user narrative. only works when creating the bookmark, if editing/deleting the modal is shown. This is done via the plugin initializer.
AppEvents was always a service object in disguise, so we should move it
to the correct place in the application. Doing this allows other service
objects to inject it easily without container access.
In the future we should also deprecate `this.appEvents` without an
explicit injection too.