Teach keyset_connection multiple attribute order

ee/app/models/design_management/design.rb

lib/gitlab/graphql/connections.rb

...b/graphql/connections/keyset/conditions/base_condition.rb

...aphql/connections/keyset/conditions/not_null_condition.rb

...b/graphql/connections/keyset/conditions/null_condition.rb

lib/gitlab/graphql/connections/keyset/connection.rb

lib/gitlab/graphql/connections/keyset/order_info.rb

lib/gitlab/graphql/connections/keyset/query_builder.rb

lib/gitlab/graphql/connections/keyset_connection.rb

spec/graphql/features/authorization_spec.rb

spec/graphql/gitlab_schema_spec.rb

.../connections/keyset/conditions/not_null_condition_spec.rb

...phql/connections/keyset/conditions/null_condition_spec.rb

.../lib/gitlab/graphql/connections/keyset/connection_spec.rb

.../lib/gitlab/graphql/connections/keyset/order_info_spec.rb

...b/gitlab/graphql/connections/keyset/query_builder_spec.rb

.../lib/gitlab/graphql/connections/keyset_connection_spec.rb