Add customizable user roles (#18641)

* Add customizable user roles

* Various fixes and improvements

* Add migration for old settings and fix tootctl role management

app/lib/admin/system_check/database_schema_check.rb

@@ -1,6 +1,10 @@
 # frozen_string_literal: true
 
 class Admin::SystemCheck::DatabaseSchemaCheck < Admin::SystemCheck::BaseCheck
+  def skip?
+    !current_user.can?(:view_devops)
+  end
+
   def pass?
     !ActiveRecord::Base.connection.migration_context.needs_migration?
   end