Add customizable user roles (#18641)

* Add customizable user roles

* Various fixes and improvements

* Add migration for old settings and fix tootctl role management

spec/controllers/admin/report_notes_controller_spec.rb

@@ -3,7 +3,7 @@ require 'rails_helper'
 describe Admin::ReportNotesController do
   render_views
 
-  let(:user) { Fabricate(:user, admin: true) }
+  let(:user) { Fabricate(:user, role: UserRole.find_by(name: 'Admin')) }
 
   before do
     sign_in user, scope: :user