Move the auto merge merge request widget state into GraphQL

Move the auto merge states for the merge request widget into GraphQL.

I think both of these components should be sorted together https://gitlab.com/gitlab-org/gitlab/-/blob/master/app/assets/javascripts/vue_merge_request_widget/components/states/mr_widget_auto_merge_enabled.vue & https://gitlab.com/gitlab-org/gitlab/-/blob/master/app/assets/javascripts/vue_merge_request_widget/components/states/mr_widget_auto_merge_failed.vue