Add customizable user roles (#18641)

* Add customizable user roles

* Various fixes and improvements

* Add migration for old settings and fix tootctl role management

app/policies/application_policy.rb

@@ -8,8 +8,6 @@ class ApplicationPolicy
     @record          = record
   end
 
-  delegate :admin?, :moderator?, :staff?, to: :current_user, allow_nil: true
-
   private
 
   def current_user
@@ -19,4 +17,8 @@ class ApplicationPolicy
   def user_signed_in?
     !current_user.nil?
   end
+
+  def role
+    current_user&.role || UserRole.nobody
+  end
 end