Add more granular OAuth scopes (#7929)

* Add more granular OAuth scopes

* Add human-readable descriptions of the new scopes

* Ensure new scopes look good on the app UI

* Add tests

* Group scopes in screen and color-code dangerous ones

* Fix wrong extra scope

app/controllers/api/v1/notifications_controller.rb

@@ -1,7 +1,8 @@
 # frozen_string_literal: true
 
 class Api::V1::NotificationsController < Api::BaseController
-  before_action -> { doorkeeper_authorize! :read }
+  before_action -> { doorkeeper_authorize! :read, :'read:notifications' }, except: [:clear, :dismiss]
+  before_action -> { doorkeeper_authorize! :write, :'write:notifications' }, only: [:clear, :dismiss]
   before_action :require_user!
   after_action :insert_pagination_headers, only: :index