When we show the links to installed plugins in the admin
sidebar (for plugins that have custom admin routes) we were
previously only doing this if you opened /admin, not if you
navigated there from the main forum. We should just always
preload this data if the user is admin.
This commit also changes `admin_sidebar_enabled_groups` to
not be sent to the client as part of ongoing efforts to
not check groups on the client, since not all a user's groups
may be serialized.
This changes the Plugins link in the admin sidebar to
be a section instead, which then shows all enabled plugin
admin routes (which are custom routes some plugins e.g.
chat define).
This is done via adding some special preloaded data for
all controllers based on AdminController, and also specifically
on Admin::PluginsController, to have the routes loaded without
additional requests on page load.
We just use a cog for all the route icons for now...we don't
have anything better.
* DEV: Add a dedicated Admin::StaffController base controller
The current parent(Admin:AdminController) for all admin-related controllers
uses a filter that allows only staff(admin, moderator) users.
This refactor makes Admin::AdminController filter for only admins as the name suggests and
introduces a base controller dedicated for staff-related endpoints.
* DEV: Set staff-only controllers parent to Admin::StaffController
Refactor staff-only controllers to inherit newly introduced
Admin::StaffController abstract controller. This conveys the
purpose of the parent controller better unlike the previously used parent
controller.
