Extract slot name constants from ReportSection

app/assets/javascripts/reports/components/report_section.vue

@@ -3,7 +3,7 @@ import { __ } from '~/locale';
 import StatusIcon from '~/vue_merge_request_widget/components/mr_widget_status_icon.vue';
 import Popover from '~/vue_shared/components/help_popover.vue';
 import IssuesList from './issues_list.vue';
-import { status } from '../constants';
+import { status, SLOT_SUCCESS, SLOT_LOADING, SLOT_ERROR } from '../constants';
 
 export default {
   name: 'ReportSection',
@@ -152,12 +152,12 @@ export default {
     },
     slotName() {
       if (this.isSuccess) {
-        return 'success';
+        return SLOT_SUCCESS;
       } else if (this.isLoading) {
-        return 'loading';
+        return SLOT_LOADING;
       }
 
-      return 'error';
+      return SLOT_ERROR;
     },
   },
   methods: {

app/assets/javascripts/reports/constants.js

@@ -25,3 +25,11 @@ export const status = {
 
 export const ACCESSIBILITY_ISSUE_ERROR = 'error';
 export const ACCESSIBILITY_ISSUE_WARNING = 'warning';
+
+/**
+ * Slot names for the ReportSection component, corresponding to the success,
+ * loading and error statuses.
+ */
+export const SLOT_SUCCESS = 'success';
+export const SLOT_LOADING = 'loading';
+export const SLOT_ERROR = 'error';